How high can water be "wicked" upward?

For scientific boffs out there........ your input would be greatly appreciated.

I am very interested in this system here ....... but interested to see if I can design an aquaponics system that needs no pumping within the system because I like to use algae bloom in the fish pond to feed my tilapia. Algae blocks pumps. Algae is fully sustainable and excellent tilapia food... they even filter it through their gills to get more... and is very high in omega 3.. and good protein source I have read.

Their system set-up is.....  Fish pond... to gravel bed for bacterial action to change ammonia to nitires to nitrates... and then they PUMP up to the grow bed above..... the water runs just below their growbed ..... and coir wicks it up to the plants ..... and the rest flows back to the fish pond.

I want to wick the nutrient water up without using a pump... perhaps using a solid tower in the center linking gravel bed and growbed above...... but not sure if this is adequate. Can't really see why it wouldn't be......... ?

I would top up the fish pond from my well. My well pump is already fully operational for the house. Needed for that... but want to avoid fiddling with extra pumps if I can think my way past it. If water can be wicked up to quite a nice height this could work I think.

Hope I am making sense.

Chelle

I don't think you'll be able to cycle water with just capillary action.  capillarity works because the polar water molecules are attracted not only to other polar water molecules, but also other materials.  the water doesn't stop being attracted to the other material just because it gets as high as you want it to, so it will still hang onto the wicking material and not flow back downhill.

capillarity is crazy, though.  water travels to the tops of trees partly by capillary action, but it doesn't then flow down the tree.  it evaporates (transpiration) or is incorporated into cells.

Yes! You are right.... all the way to the top of trees....  I should have remembered that. Thanks for pointing it out, tel. Is what I needed.

I don't want to cycle ..... just wick it up one way to the growbeds.... then will have to top up the fish pond. But that is easy because the pump is already effectively in place for household use so I would just divert some of the water as needed to top the fish pond. One pump to run and manage instead of 2 or more.

So the next question is keeping the fish healthy.... maintaining water quality without recycling as in a standard AP system.

If I pulled the waste from the bottom of the pond via a Solids LIfting Overflow...
Here is a pic courtesy of TCLynx on Backyard AP to show what I mean about a Solids Lifting Overflow.... rest of the diagram not relevant for this idea I am chewing over..... pump needed from sump back to fish pond and I am trying to avoid this.



Waste does generally settle on the bottom.... lifted up as the pond is topped up.... and drawn off into gravel beds that are rich in bacteria that effect the nitrogen cycle.... from ammonia to nitrates which plants can use..... this is wicked up as a nutrient rich colution to grow beds above.... I would have to have the wicking medium all the way down into the base of the gravel bed to keep draw water up even when the gravel bed is low..... then when I see it is low I top up the fish pond and get it to start all over again.

I need to establish how many grow beds would draw off enough water so that top up is enough to keep water quality good for the fish.

This would be a system so low tech that power failures would not be disasterous... and algae... so economic and nutritious.... could be used to feed the fish. No pump to get clogged.

I wonder if I am missing something?

Chelle

sure, you can wick into your grow beds.  some of the dirt in the beds just has to be in contact with the fishy water.  it will pick up whatever nutrients are in solution, but not much particulate matter.  a periodic clean-out with a shovel might be enough to take care of what collects on the bottom, depending on the scale of your setup.

Neat.

I am hoping the SLO will lift most of the detritus from the bottom of the fish pond up into the gravel bed ............ and that bacteria effecting the nitrogen cycle will make it more soluble and accessible to the plants in the grow bed above. This I will have to see.... if it doesn't then maybe sweeping it looser to resettle more lightly will aid in this.... or if not then.... as you say.... a spade at intervals. But that would mean draining the pond and I hope not to do that. I am a true Premie.... find how nature will do the work for me! 

Appreciate your thoughts, Tel. Thanks.

Chelle

You can wick waste water, but the big question lies in how many fish you intend to raise.  The real reason that pumps are important to aquaponics systems is that enough fish to create substantial gains in plant growth really produce a great deal of waste.  Amonia must be converted by the plants. 

If no water return is anticipated, you will be needing to top up the fish tank very regularly.  This becomes a problem of fish health.  You will need to become adept at duplicating the chemistry of the fish tank water.  Rapid change of environment will compromise the very part of your system that you need to remain healthy in order to take advantage of all that algae.

If you are wicking water into soil beds, it must not be allowed to return into your fish tank.  Turbidity will result and you will be killing a lot of fish. 

A good demonstration of this is the old Junior High School fish/terrarium combo.  In every case, the fish environment must be separated from the terrarium environment.  When plant roots are allowed to get down into the water and "wick" it up, the water loss must be replaced quickly.  When soil finds its way into the aquarium portion, the fish die. 

The ecosystem must be a closed loop.  If the loop is open, trouble follows.

Cloudpiler wrote:You can wick waste water, but the big question lies in how many fish you intend to raise.  The real reason that pumps are important to aquaponics systems is that enough fish to create substantial gains in plant growth really produce a great deal of waste.  Amonia must be converted by the plants. 

Would the algae not also be utilizing the waste?

I have a system going at the moment in an old reservoir where I have to add cow manure to get algae growth .......and so adding more fish would presumably do this instead? There seems to be a strong nitrogen cycle operating ....... converting from ammonia to nitrates ...... in the water already because even when I throw in lopped branches of mulberry for them to feed on the branches sometimes grow back leaves .... and twice I have even seen some grow mulberries!  Just lopped off branches....

If no water return is anticipated, you will be needing to top up the fish tank very regularly.  This becomes a problem of fish health.  You will need to become adept at duplicating the chemistry of the fish tank water.  Rapid change of environment will compromise the very part of your system that you need to remain healthy in order to take advantage of all that algae.

Interesting point. However, I am currently doing this with my fish at the moment and they are doing really well... have been for 3 years now. The sudden addition of well water has not compromised health. I do have a very hardy fish though... tilapia. Top up can be as much as one third at a time sometimes because there is a slow leak in the reservoir that I am raising them in. I think with a less hardy fish this would probably be a problem ... especially with city water... mine is not full of chemicals.

If you are wicking water into soil beds, it must not be allowed to return into your fish tank.  Turbidity will result and you will be killing a lot of fish.

Yes, for sure. But this is not a cycling system I am considering. I want to avoid that because it means pumps.... and algae is death to a pump... algae being the main reason I am looking into this possibility.

A good demonstration of this is the old Junior High School fish/terrarium combo.  In every case, the fish environment must be separated from the terrarium environment.  When plant roots are allowed to get down into the water and "wick" it up, the water loss must be replaced quickly.  When soil finds its way into the aquarium portion, the fish die. 

I need to post a pic... I see I didn't explain well enough....  I'll get a sketchup model pic and post it. The plants are not in soil just above the pond.... separate unit...

So from the fishpond water gravity feeds into gravel beds... where nitrogen cycle converts ammonia to nitrites and then nitrates.... and a centre column from here reaches up into the growbeds above so that water will be wicked up to the plants. Not sure my medium I will use is soil... might be compost... the link I posted used coir.

The ecosystem must be a closed loop.  If the loop is open, trouble follows.

Depends how it is done ........... and with which fish I think.

Having a system that is dumping your topsoil into the pond would be dumb but having beds with another medium would be fine... even floating in the water would be fine if properly held together. The system I am modelling my thoughts on used coir... Tilapia are also amazingly forgiving of poor water quality... so definitley these factors would need to be taken into consideration.

Thank you very much for your thoughts, Cloudpiler.

Chelle

i think it's a big question of which fish you'll use.

this guy  http://www.youtube.com/watch?v=MaZNGTiVhPQ

used lobster (though it was a different kind of system)

i might suggest carp. they reproduce very rapidly, get quite big, and survive almost anything. so little mistakes can probably be ignored. and they will eat almost anything too...

a lot of people in the u.s. think of them as a trash fish. but if you do a little research, you find thomas jefferson had a carp pond he would eat from, and the reason carp are everywhere is because in the 1800's, the government planted the carp as a food source for the people moving west.

the Jewish people eat carp for a religious holiday,        bah! i think after this post i will post a new thread, in praise of carp!

Algae utilizes waste in much the same way as plants, with one big exception.  Algae can also make the water turbid enough to compromise the fish's ability to take oxygen from the water.  Tilapia is a wonderful fish for this, however, as they can take a whole lot more algae than many other species.

If water is being used to feed plants in grow beds, the plants utilize not only the waste but also a great deal of the water.  Evaporation takes more, and then, as you mentioned, there are always leaks.  In fact, if you are wicking up to your plants, chances are you are also wicking out of the system.  Water is behaves in interesting ways.  Your well water sounds just right.  But the whole point of wicking water is to avoid the use of pumps.  Delivery of water is a big issue.  Now, if the only issue you have with pumps is the algae, then the well pump isn't a problem.

The whole idea behind Aquaponics (and it's a good idea) is to use the ammonia being created by the fish to grow food.  The plants do a good enough job to keep your fish healthy, but just good enough.  The best medium to use actually should not contain soil, as much of the ammonia will be used by the soil organisms to create methane, instead of nitrogen, and again, the return to the water will be turbidity - bad for fish.

Hey blot101.... nice video! "How to Build a Million Dollar House Dirt Cheap!" Must have got the urls mixed.... but I have watched this before and was really interesting 

A carp thread is a good idea! So is a tilapia thread!

Cloudpiler, good point about algae causing a problem with too little dissolved oxygen. A balance must be ensured.... I have not had a problem with this so far... but I don't keep algae levels constant.... I feed manure for it and then let it be eaten.... feed mulberry etc in between... and then do it again. I would run this new AP system fish pond that way too I think.

I hope with the new pond I am building I will have no leaks. Have been testing out on tiny ponds in my food forest (for frogs etc ) to get this right. So I will move from the point of no pond leaks and then have to accomodate only evaporation from the plants in the growbeds .... hopefully! 

The next thought is that I will have to have enough growbeds to effect enough evaporation so that top-up is enough to keep water quality good for the tilapia.

Or have a lot of beds and have a valve gate that can determine which bed or beds are to be gravity fed with water from the pond. The wicking will be slower to irrigate than normal AP cycling of water..... but also last longer in the holding medium..... probably well matured compost.

The pic is a quick sketchup diagram to show one unit.... gravel bed underneath.... this receives the gravity feed from the pond.... tower in the center linking with the top growbed. No exit. Only evaporation.... but this will keep the plants nicely watered for quite some time without drowning.... really low maintenance.... just have a pipe in the gravel bed right down to the bottom to insert a water level measuring stick to see when the next load of water to come in. I bet I could even go away for days with this system.... no fear of power or pump failure and water starved plants.

Yes... by only using my regular pump to top-up the pond I avoid any algae clogging of pumps used in water delivery. And no extra pumps to monitor and maintain. Algae can easily get through I have been told.... and also breed up once a little has been introduced in pump. Not good.

The whole idea behind Aquaponics (and it's a good idea) is to use the ammonia being created by the fish to grow food.

Exactly... I don't want to waste it. Or the nutrient rich detritus.

The plants do a good enough job to keep your fish healthy, but just good enough. 

I think top-up is even better than only relying on bio-filtration by the plants..... The algae will do some bio-filtration.... and I may introduce some others along the side to aid in developing a more complex system.... which is always more beneficial. Permie principles apply here too....

The best medium to use actually should not contain soil, as much of the ammonia will be used by the soil organisms to create methane, instead of nitrogen, and again, the return to the water will be turbidity - bad for fish.

That is what the gravel beds under the growbeds are for..... the full nitrogen cycle will be effected here and then the nitrates in solution will be wicked up to the plants..... that is the theory anyway. Posting here to have any flaws revealed.... so again much thanks for all thoughts.

Chelle

Hi Chelle,

Gary Donaldson, in AU, says that they have found that the maximum height you can wick water upwards is 300mm.  More wicking materials in the soil, the better.  I had 4 wicking containers over the summer as an experiment.  The soil was bulk purchased mix spiked with rabbit manure, worm castings and worms.  The containers were 400mm high, which was nice as it left a reservoir of 100mm for the water.  I had 3 tomatoes and one winter squash.  They worked well as far as water maintenance went, like filling the bottom once a week even during sunny summer.  Still the soil quality sucked.  You  couldn't rely on a newly trasplanted plant to have the roots to really avail themselves of the system.  But top watering will they were established got them to that point.  Will try again next summer.

Where are you located? I am in coastal NW WA.  Look around norcalaquaponics.com for ideas.

Gary

Hi blot101,

I've been considering carp for my system to be for the same reasons.  Tough, hardy, cold tolerant, tasty, market for E. European folks in the area who like the fish.

I've eaten it twice in Poland, and it was great.  They used special forks with widely spaced tines to pull the meat off of the skeleton.  Will eat it ourselves to begin with.  I've been told of mirror carp and leather carp as good varieties for possible AP type set-ups.  And thanks for the video link.

Gary

gary koch wrote:
Hi Chelle,

Gary Donaldson, in AU, says that they have found that the maximum height you can wick water upwards is 300mm.  More wicking materials in the soil, the better.  I had 4 wicking containers over the summer as an experiment.  The soil was bulk purchased mix spiked with rabbit manure, worm castings and worms.  The containers were 400mm high, which was nice as it left a reservoir of 100mm for the water.  I had 3 tomatoes and one winter squash.  They worked well as far as water maintenance went, like filling the bottom once a week even during sunny summer.  Still the soil quality sucked.  You  couldn't rely on a newly trasplanted plant to have the roots to really avail themselves of the system.  But top watering will they were established got them to that point.  Will try again next summer.

Where are you located? I am in coastal NW WA.  Look around norcalaquaponics.com for ideas.

Gary

Neat. Thanks Gary. Will work around that. 300mm. It figures that the new seedlings and transplants may need a little extra top watering to get started. Good to know. Thick mulching might help with this though don't you think? Top up reservoir once a week and the new plants once a week too where needed. What you think?

I am in NW SA. Sunny South Africa. Will check out the site. Much thanks.

Chelle

I too have been looking at what would be the best method for me to use to carry water up to the top of an aquaponic system. In the near future, when we finally own some land, I will be doing some experimenting.

The desired characteristics  for my water lifting device are:

1 ) Easy to Use
If something happens to me, could my wife and kids continue to benefit from the set up?

2 ) Free, or Nearly so, to Build
Can I find a way to build this out of found and reused materials for next to no cost?

3 ) Free, or Nearly so, to Run
Can I build a water lifting conveyance that will require no fuel burning engine or electrical usage?

4 ) Sustainable
Can I build something that will stand the test of time? Will I get a good return on the time and efforts invested on the project? Or, will it self destruct in short order?

5 ) Easy to Build
I am not very knowledgeable about electrical motors, wiring, or designing such systems. Keeping this device to a more simple mechanical type will be much easier for me to design and build

6 ) Easy to Maintain
Being purely mechanical, and not containing electrical or chemical components, this device should be much easier to keep running, and spare parts may also be easier to find or fabricate should that become necessary.

7 ) Efficiency
Will the machine actually lift the amount of water I will require of it over a given period of time?

8 ) Environmentally Friendly
Will the construction and use of this device adversely effect the environment in which it will be used? Will it harm local wildlife, birds, insects, or people? Will it contribute an unacceptable amount of noise to an otherwise peaceful setting? I've heard vibrations of some windmills drive away moles. Would this device harm worms nearby working my compost pile for me? At any rate, it should certainly be clean and non polluting, using only the energy provided by the wind.

9 ) Using Recycled Materials to Build
Can this device be constructed out of entirely discarded or scavenged materials, recycling those materials and putting them to good use?

10 ) Safety
I don't want anyone losing life or limb to a machine I have created. Safety measures such as cages and guardrails will be designed into the system from the beginning.

At first I was thinking of using a windmill or a solar system to power a pump that would pump the water up to the top of an aquaponic system. Since I am not great with electrical systems, I kept looking for another idea. I found windmills that directly drive a mechanical pump that would certainly fill the water lifting requirements. However, buying such a windmill and pump is quite costly, and building such a complex system from scratch is beyond my capabilities.

In my research, I discovered a home made Vertical Axis Windmill this guy had made out of steel drum halves. He used it to generate electricity. I decided that I will someday construct my own, somewhat smaller vertical windmill. It will drive a vertical shaft which I will use to drive a horizontal pulley via universal joints. That horizontal pulley will be used to drive a long inclined rubber conveyor belt which will have small buckets (coffee cans) attached at regular intervals. The bottom of the conveyor will dip down into my sump pit and the top of the belt will dump water over the top of the highest level of my aquaponics system. I hope to replenish water into the system using the large sump pit area to hold collected rain water with a shut off that will divert the water away once the sump has been topped off.

Now, with all that said, I am still very interested in a wicking system as that sure would be a lot simpler to build and use. However, I am a bit skeptical about the effectiveness of using wicking action to move water up to the top of an aquaponic system. All the ones I have seen use a pump to do the job.

Now, with all that said, I am still very interested in a wicking system as that sure would be a lot simpler to build and use. However, I am a bit skeptical about the effectiveness of using wicking action to move water up to the top of an aquaponic system. All the ones I have seen use a pump to do the job.

Hi Will,

Interesting post.

The system I want to do.... as described initially on this thread... is not a typical  recirculation AP system..... no recirculation at all. So no wicking action to move water to the top of an AP system. I don't want to fiddle with unnecessary pumps .... or possible pump failures and fish deaths... so will only use my current house water pump which gets water to the top of the hill. This water is fed down to the fish [to top up with fresh water].... a deliberate overflow is created.... the overflow [taken from the bottom of the pond to remove the detritus] then feeds into the wicking reservoirs. That's it. No re-circulation. Very minimal effort. The wicking beds will have earthworms too. I want AP with least effort. Too busy. Once a week flood the pond with new water should do it. Easy to use. Nearly free to run. Sustainable. Easy to build and maintain. Safe for the fish and environmentally friendly. I think it a lovely Permie AP solution..... fish and plants and earthworms with little labour and little water used. Can't tell you about cost... depends what you use to build it. I don't mind a little initial spend - but always go for minimal monthly overheads.

i haven't noticed if the water movement requirement is continuous or cyclical - if cyclical, and considering the diagram in the 1 may post - the flow pattern could be created by manually elevating and lowering the sump tank at the right side of the diagram - some design modifications would be needed but nothing very complicated and the need for a  pump is avoided -

another alternative would be to use a mechanical pump - a manual pitcher type hand pump - to periodically transfer water from the lowest sump tank to an elevated storage tank to drain by restricted gravity flow into the fish tank -

Chelle Lewis wrote:
Hi Will,

Interesting post.

The system I want to do.... as described initially on this thread... is not a typical  recirculation AP system..... no recirculation at all. So no wicking action to move water to the top of an AP system. I don't want to fiddle with unnecessary pumps .... or possible pump failures and fish deaths... so will only use my current house water pump which gets water to the top of the hill. This water is fed down to the fish [to top up with fresh water].... a deliberate overflow is created.... the overflow [taken from the bottom of the pond to remove the detritus] then feeds into the wicking reservoirs. That's it. No re-circulation. Very minimal effort. The wicking beds will have earthworms too. I want AP with least effort. Too busy. Once a week flood the pond with new water should do it. Easy to use. Nearly free to run. Sustainable. Easy to build and maintain. Safe for the fish and environmentally friendly. I think it a lovely Permie AP solution..... fish and plants and earthworms with little labour and little water used. Can't tell you about cost... depends what you use to build it. I don't mind a little initial spend - but always go for minimal monthly overheads.

It is possible to make a natural pond for aquaculture using plants only and specific shapes of the pond in order to encourage natural water movement through the pond.  I would suggest reading up first on natural ponds as they are used in Europe for swimming.

I will, also point this out about Tillapia.

However, farm raised tilapia (the least expensive and most popular) has a high fat content (though low in saturated fats). According to research published in July 2008, farm raised tilapia may be worse for the heart than eating bacon or a hamburger. The research suggests the nutritional value of farm raised tilapia may be compromised by the amount of corn included in the feed. The corn contains short chain omega-6s that contribute to the buildup of these materials in the fish. "Ratios of long-chain omega-6 to long-chain omega-3, AA to EPA respectively, in tilapia averaged about 11:1, compared to much less than 1:1 (indicating more EPA than AA) in both salmon and trout." Wide spread publicity encouraging people to eat more fish has seen tilapia being purchased by those with lower incomes who are trying to eat a well balanced diet. The lower amounts of omega-3 and the higher ratios of omega-6 compounds in US farmed tilapia raise questions of the health benefits of consuming this fish.

Wake Forest University Baptist Medical Center (2008, July 10). Popular Fish, Tilapia, Contains Potentially Dangerous Fatty Acid Combination. ScienceDaily. Retrieved July 11, 2008, from www.sciencedaily.com

If I was still in my store back east, as a professional pond, & custom aquarium design and building company I would strongly suggest

Since I woke up and encourage people to think outside the box now, I commend you on your adventure.  There is a section on Natural ponds for aquaculture in the Permaculture Designers Manual but it is fairly glib.  I would suggest reading up in a book like, Natural Swimming Pools: Inspiration For Harmony With Nature.

Lastly, have you considered growing them with food crops like rice?  In some countries they put the fry into the paddie with the rice.  When the rice is ready for harvest the fish are of edible size.

Interesting comments. Thanks Pakanohida.

I want to do something a little more controlled and productive than just a pond.... hence the growbeds that are wormbeds too. The tilapia are voracious gobblers of any plants I put in their pond. I will read up on Natural ponds though.

With regard to tilapia. I have read that article. I think it is true about commercially raised tilapia. I do not rear mine the usual way. They are naturally designed to sift out algae and so I mostly feed mine on algae, mulberry leaves and fruit peels. Algae is one of nature's richest sources of Omega 3 fatty acids. This kind of diet does not produce the usual commercially reared product I suspect. I am not in a race with time to produce large fat fish for sale. Everything I do must be natural and follow natural cycles. I am more interested in producing diverse and multiple products than majoring on one and forcing growth through the contrivance of expensive technologies. I know I am fortunate in having the time and space to develop multiple naturally developed products.

The very reason that I cannot do a standard AP system is because I use algae as a food source. It would clog up pumps etc in a recirulating system..... so I just will gravity feed down to growbeds that are wicking beds.

I have been trying to access rice seed for some time now. I may try fish and rice together then. There is already a place I have ear-marked for this should I manage to get my hands on some seed.

Your comment on "specific shapes of the pond in order to encourage natural water movement through the pond" really interests me. I will be using flowforms to introduce the water into the pond for all the benefits they offer.... but the idea of shaping the pond to effect natural movement of water within the pond is new to me. Would you not have to get the water moving mechanically to benefit though?

Chelle

Chelle, I don't know what your water situation is, but it makes more sense to me to use grey water to top up your pond rather than fresh water.  I'm not suggesting routing raw grey water directly to your pond, but setting up some simple treatment beds and tanks to run the grey water through first on it's way to the pond.

maybe you're not set up to separate grey water, but it seems like a better use of a limited resource.

That is actually a marvellous idea Tel. It is going to take some time and ingenuity because I am not set up in any way for this... but I won't forget this idea! Thank you.

Clean it up through marsh plants and then get it to the pond. I would have to store and then top up the pond in one go from time to time to get enough flow to pick up the detritus from the bottom of the pond. I will overflow from below.... using a Solids Lifting Overflow.

Chelle

why not "floating islands" for your plants?
http://www.biofloatingislands.com/

divide the pond into three sections with netting to contain the fish.
one section - fish
one section - floating island
one section open for algae growth
recirculate water with "solids lift tube and air bubblier" see air lift tube
water flow - fish -> island -> algae -> back to fish
water returns cleaned and full of food
netting keeps fish from destroying roots of plants and creatures that help break down solids

Hi Duane,

Nice set-up you are describing.

I have planned to use some plants in the pond but not main production plants. I prefer to use the water for the fish and use the land around for plants..... It would be more productive in my set up.... I have the space so prefer the wicking beds as growbeds because I can have the earthworms too.... really up the nutrition. Straight AP seems to always need nutritional boosting.

But appreciate the input. Interesting concept.

Chelle

Chelle
In my search for appropriate greywater systems I learnt the value of baffles in the growbeds. Force the water to be exposed to plants roots a longer time.

I am investigating using solar too - very expensive but may be glad it was done in the long run... soon

Rustenburg NW

Jack

I have to question the idea of feeding grey water to fish that I might be eating.  You would have to be extremely vigilant that only biodegradable materials are used, and these still might poison the fish.  It would be better to feed the grey water to a bog filtration system to clean it up before going to the fish.

How are you planning to accommodate oxygenation of the water for the fish?  A simple trickle of water might not provide enough, perhaps adding some water plants would help, in the fish tank.

So, you are planning an open-circuit aquaculture system.  There was a gentleman down in Australia doing that, but I believe he pumped the water to the plants.

Have you heard of wicking beds?  www.waterright.com.au  Remember, your plants need oxygen to the roots also, they cannot sit permanently in water or they will damp off and rot.  Most vegetable plants will, anyway.

Jen0454 wrote:
Chelle
In my search for appropriate greywater systems I learnt the value of baffles in the growbeds. Force the water to be exposed to plants roots a longer time.

I am investigating using solar too - very expensive but may be glad it was done in the long run... soon

Rustenburg NW

Jack

Jack, this sounds interesting. How does this expose the roots to water longer? Exactly what kind of baffles? Any diagrams you could point me to? Or pics? I am also interested in using alternate energy. Might prove really economical in the long run, as you say.

Chelle

Will Sustane wrote:
Now, with all that said, I am still very interested in a wicking system as that sure would be a lot simpler to build and use. However, I am a bit skeptical about the effectiveness of using wicking action to move water up to the top of an aquaponic system. All the ones I have seen use a pump to do the job.

I am not interested in a recirculating system, Will. I don't think moving water back up to the top of an aquaponic system is possible with wicking.

My wicking beds will be fed from the fish pond in my system and then the pond is topped up from my well. I pump for the house already anyway and will just divert water to the pond as needed. One pump to maintain...

I have thoroughly investigated recirculating AP and don't want to fiddle with extra pumps and pH and possible failures. My tilapia are acclimated to my well water and the full range of temperatures here. I will just be adding "aquaponics" by installing wicking growbeds below the fish pond... good use of nutrifying pond water. Minimal maintenance. A more permaculture style of AP

PaulB wrote:
I have to question the idea of feeding grey water to fish that I might be eating.  You would have to be extremely vigilant that only biodegradable materials are used, and these still might poison the fish.  It would be better to feed the grey water to a bog filtration system to clean it up before going to the fish.

I don't think anyone is suggesting using greywater for the fish, Paul.

How are you planning to accommodate oxygenation of the water for the fish?  A simple trickle of water might not provide enough, perhaps adding some water plants would help, in the fish tank.

I will be using flowforms into a waterfall to increase oxygen.

So, you are planning an open-circuit aquaculture system.  There was a gentleman down in Australia doing that, but I believe he pumped the water to the plants.

I am on a slope. Gravity will feed the growbeds below. No pumping required.

Have you heard of wicking beds?  www.waterright.com.au  Remember, your plants need oxygen to the roots also, they cannot sit permanently in water or they will damp off and rot.  Most vegetable plants will, anyway.

The wicking bed is designed to carry water to the base of the bed and get wicked up to the roots... no roots permanently standing in water.

Chelle
The baffles are placed so that the water flows in a zig zag fashion extending the length the water needs to travel before exiting the bed.
I would use something like fibre cement panels as used for ceilings in SA these days. "Nutek" can get at "Builders"
or you could build brick walls all depending on the construction of your tanks.
One diagram on this page - just below "How to build one"
http://frogs.org.au/frogwatch/greywater.php
and below these words...
"A tank can be baffled any number of times to achieve the desired flow path"
from here - http://www.biofilters.com/LONGPATH3.htm

Although the top one is for greywater it would work well since it is just a biofilter.

Ah! Jack I really like this idea.  One of my concerns was for the young plants that could not reach down to the wicked wet area yet. Hence my original question that started the thread....


Reversal to the diagram... fish to baffled wicking beds... slow the water flow long enough to even reach younger plants... but outlet to next baffled area in the growbed prevents overflow... needs to be manually adjustable I think. In extremely hot weather I would get the Solids Lifting Overflow [SLO] to lift the solids from the bottom of the pond into the base of the growbed's first baffled area... carefully watching to see at what point I needed to open the outlet from 1st baffled area to next ... etc. This would ensure a good soaking once a week and yet not drown my worms because just a flooding to wet and on again. I would have a lip of about 200mm below the water exit point to retain the wicking action once the manual flood and drain had been effected. This process would probably only need to be done once a week... unless unusually hot and dry.

My wicking beds will be undercover so rain doesn't flood it all. I think transparent roofing that runs off into a gutter diverting into the pond would be excellent... but able to divert to a tank if rainfall is heavy. You really got me thinking!!!

Such a neat little tweak to the system! Much appreciated for the input.

Thanks!
Chelle

Chellie, don't get me wrong, I'm not against your idea.  As you have plenty of well water, your ideas may work well.  I'm just wondering the scale of your project.  The fish pond requires constant oxygenation to maintain the health of the fish.  BTW, you can raise duckweed in a seperate pond or tank to feed the fish, as tilapia are vegetarians. 

Due to the slope of your property, you can use a siphoning system that can be regulated with a valve to control the amount of flow into the plant beds, but you will also need a bypass valve for when the plant valve is shut or closed to a trickle, as you have a constant imput of water.  That water has to go somewhere.  Of course, if you are planing to have extensive plant beds, you might be able to use a manifold system to divert water from one bed to another which would help, but as you have a constant inflow to the system, you have to have a constant outflow to prevent overflow of the fish tank/pond.

Evaporation and transpiration by the plants will take up some of the water pressure, but probably not all, especially in event of rainfall.

In a properly functioning wicking bed, using peat, coir, or other spongy material, the water will be constantly wicked up to the surface.  There would be plenty of water available to your young plants, not just the mature ones.  Of course, you would want the water to flow into the system for a week or more to ensure proper wicking prior to planting.  The growing media ideally should have the consistancy of a damp sponge, not soaking wet.

In a wicking bed, you are creating a growing environment, including an artificial water table.  This water table is regulated by drains which allow excess water to flow out of the bed.  This drain can be connected to another, slightly lower bed in a cascade fashion.  Idealy, you want the water to wick up from the water table below toward the surface, not the other way around.  Top watering often carries the water and nutrients below the root zone, flushing it away and starving the roots.  Wicking does just the opposite, as I am sure your research has demonstrated.

Inclusion of worms in your plant beds can also increase the amount of nutrients available. Redworms, used in vermiculture, are especially good at this, provided you supply them with rotting plant matter.  They do not eat living plants.  There is an added benifit in that they provide oxygen to the roots through the tunnels that they dig, loosening the soil.

All in all, this is a good permaculture solution, IMHO.

Chelle
I get what you want to achieve now.
-You want to grow using the water - then open a baffle to fill the next growing space with water ...

I once made some "self-watering containers" for growing tomatoes similar to "earthboxes"
There's quite a bit online if you search these words.

The growing medium included a lot of Coco Peat, some Vermiculite and Peat. It wicked well.
The growing medium is separated from the lower water reservoir and a tub is placed right down into the water that wicks into the growing medium.
The depth of the water is controlled with an overflow hole so it will not touch the bottom of the growing medium and get it waterlogged.
You can have flow of water through the grow beds - but very slowly.
I did find that the roots of the plants went right down into the water and one tomato drank about 5-6liters of water a day in summer !
I can send you a drawing to illustrate.
Jack

Yes, Jack. Basically a self-watering system that is filled below from the pond... so nutritious. Earthworms will probably thrive and maintenance is minimal. I want to go as low tech... low cost... low overheads... low maintenance...as possible. So it is not conventional AP... more Permie style AP.

I like topping up the fish pond from the well... fresh... easy .... and already in place. Recirculation.... like in conventional AP.... takes a lot of monitoring because the balance has to be best for the fish and the plants. With soil filled with wicking material.... and even pockets of kitchen waste.... as the growing medium there is less need for checking pH.. nitrates.. etc.... the growing medium will adjust pH for the plants... and clean water will prevent pH spiking for the fish. Best of both worlds I think. Heavy mulching would reduce evaporation too.

I would really appreciate any drawing that you have.

Chelle

Thanks Paul.

Project will be large scale. Less volatile... easier maintenance. Pond will be 11m x 3m... and many growbeds below. I will just keep adding more growbeds until the balance with the fishpond is best.

Chelle

Hi there, I was wondering if you've figured out a way to cycle the water without the use of a pump. When I eventually get my own land I want to try and be as self-sufficient as possible and grow all my own food on as little electricity as possible. A precaution for those "what-if" scenarios where the power goes out or something. I want solar power but I'd still like to know if it is doable. My thinking is that when you plug a sink, fill it with water, and then pull the plug gravity is forcing it down and there's enough force to push it through the pipes. Same idea with a drink and a straw -- gravity pushes on the fluid in the cup as well as through the straw, making an equal push so it doesn't move. When you suck the air through the straw there's no more gravitational push on that end and gravity pushes the fluid down and it comes up through the straw. Is it possible that a big enough container filled with enough water will have enough gravity pushing down on it that it will be able to force it's way up a tub and into the grow bed, where it will then drain down back into the fish tank, all on its own?

I'll probably need some way to add water to the system regularly as this would only be plausible if there is a certain amount of water and once the water runs low it would have to be re-primed. Like a manual siphon for cleaning aquarium tanks.

Brittany Johnson wrote:Same idea with a drink and a straw -- gravity pushes on the fluid in the cup as well as through the straw, making an equal push so it doesn't move. When you suck the air through the straw there's no more gravitational push on that end and gravity pushes the fluid down and it comes up through the straw.

Gravity is still acting on the water within the straw when you suck in. When you aren't sucking on a straw, about 30 pounds of air per square inch above the glass is pressing down on the water inside and outside of the straw. When you suck on a straw, you decrease the pressure of the air pressing down on the straw.

Brittany Johnson wrote:Is it possible that a big enough container filled with enough water will have enough gravity pushing down on it that it will be able to force it's way up a tub and into the grow bed, where it will then drain down back into the fish tank, all on its own?

Nope, but if you have a large quantity of water moving down, you can use that water to push a smaller quantity of water above the tank. There are several threads about 'ram pumps' that use this technique.

I read most of this and did not see this idea. I have been trying to work out a simple heat diferencial pump where the sun is focused on a medium which draws the water from a colder point below. It seems you could maximize the wicking effect by focusing sun light with a simple parabolic shape which would increase the flow? Not sure if it would effect other aspects of the aquponics as I know heat can increases algie.

Mikael

I may be late to this thread, but I have something to contribute...

First, it depends on how you have your system set up. If this is about good aquaponics, you would want the best water quality for the fish, and it of course depends on at what level the fish and the plants are ate respectively.
If you try this with any solids of any sort in the water, it is quite possible that whatever you use may eventually get clogged up with whatever solids are involved.
However, on theother hand, if you can/are going to use the wicking/cappilary action for water with the least amount or no solids, that would work better.
You could use this method to lift water UP to whatever you have the fish in.
Although obviously and seemingly the opposite of popular methodology and practice, you CAN have the fish higer than the plants, and use gravity allow the water to go back down to the plants; this part is easy, of course.
Something I am tempted to play with or use is fairly narrow/young palm tree trunks (young or narrow due to the size and weight and handling them, etc.) due to thier make-up and cappilary/wicking potential.
I also intend to use a number of methods complimenting each other, including a DIY wimdmill pump.
One reason I am thinking about using Palm trunks is the sheer potential for the amount of water it/they might be able to transport due to thier diameter, which is much greater than the average wick, tube, etc.
Another reason is that I will be doing this in the desert, where there is little to no practical potential for a well, and where saving water and using as little power as possible is involved, and also so that I have a system that works naturally, so that there is little or no potential of things going wrong because of some power outage, or a failed electrical pump, etc.
I am currently studying hwo high water can be lifted through cappilary action/wicking to make my final decision. For my needs, no more than a few feet would be necessary, and if that works out, the only consideration left is the potential volume of water than can be moved - thus, again, I am looking into the potential for using Palm trunks.

I understand that you are probably doing like everybody else does, with the fish/water lower than the plants of course, and probably don;t want to re-figure and/or rebuild everything to make a system that to many would seem backwards.
Another reason I am seriously considering a system where the fish/water is/are higher than the plants was from the idea of using a bubble lift. If I were to use a bubble lift, it would make more sense to use it to bring the water UP to the fish container, as it would oxygenate the water to some extent at the same time.