Mark Reed

Mine is one of those preformed plastic things, it's less than three feet deep. Our weather now is such is that thick ice rarely forms but on occasion the ice can get six inches thick. A few Endlers and Japanese rice fish have survived that, and I thought I was on the way to breeding for even more cold tolerance, but someone decided they could drop in some bluegills to net out to clean and eat the next day, and that was the end of my little fish.

Every time a thread about playing with water/plants/fish comes up it fires up my want to about building a bigger pond. I may actually tackle it this spring; I have plenty of space and a piece of liner doesn't cost all that much. Just have to decide what I really want, to raise aquarium fish to sell, to raise a bit of fish, clams or whatever to eat, or just to have fun.

Some of your description and logic seems pretty sound, and interesting. Actually, the whole part about your own set up sounds pretty interesting. I wouldn't mind seeing such a contraption in person. Maybe the parts that I'm still not sold on would fall in line. I still would not want one myself, at least not in our current house. Here, the little free standing Vermont Castings does fine.

I guess I do cheat a bit.
The house is small, well insulated and partially underground with big south windows. As mentioned before the bricks around and under as well as the chimney itself serve as heat sinks.  They absorb heat from the stove and the windows both. It was all built that way on purpose. The stove has a double wall and a lever to close the chimney forcing smoke out through the coals at the bottom. *That only works while the chimney is hot, but I'm fine with that. Once the chimney is hot, the draft continues until all coals are fully cooled.  A little smoke comes out of the chimney when I start a fire but almost nothing visible comes out once that lever is set. I just load it up based on, do I want it to roar for 1/2 an hour or do I want it roar for two hours. I also have an abundant free source of seasoned black locust firewood, basically in the yard. That was also by design. I guess by volume I burn about fifty cubic feet of actual firewood in a season.  Black locust as a bonus drops a lot of sticks which we use for small quick fires when it isn't cold enough outside for a real fire.

In the early days many people insisted that a normal vertical chimney was not needed,now most people involved in the making of rocket mass heater seem to think it is best practice to use these kinds of chimneys.

It's good to know that most people are now realizing a vertical chimney is necessary to achieve a good safe draft. I think you need a good draft just to start a fire, if you don't want a face full of smoke, and it needs to get hot fast to heat the chimney and establish the draw. I think if you remove the issue of horizontal movement and extracting ALL of the heat before exhaust then you have removed any issues I might have.  

Yes, I suppose some might see it as wasting heat, but it is critical that the chimney itself gets hot and stays hot.  Our masonry chimney, not on an outside wall, itself, works as a mass heater. My little wood stove puts off a pretty good roar if it's cold enough outside to warrant it. So, I guess I already have a rocket mass heater, of sorts.

I said I don't know what a rocket mass heater is because I see basically two different things and I never know for sure what the person is talking about. One is the simple, small sized fire box surrounded by or buried in a heat absorbing and fireproof material like brick or stone and with a vertical exhaust.  That is basically what I have with my wood stove except since mine is an actual stove and the heat absorbing material isn't in direct contact with the fire mine isn't quite as efficient as it might be if it was a true masonry type construction. Still, I really do burn 1/10 or less wood than most people I know who have big wood stoves and my house stays more comfortably warm than theirs. I don't have the periods of damn it's hot in here, alternating with its freezing, put in more wood.

The other is the type with the horizontal flow of hot exhaust. I've seen a number of videos and designs on that but never one that I would trust to operate safely. I don't see why, even if you did nice small, clean burns that creosote would not eventually build up in something like that, leading to the danger of fire. I also suspect they would be very highly prone to back drafts, when a gust of wind hit the chimney just right and blows the smoke back down. Or just flat leaking exhaust through any possible gaps or even back out through the actual air intake as a fire is in its last stages and cooling off. It seems to me that a combination of cooling but remaining coals, combined with a cool chimney and the expectation of horizontal exhaust is a recipe for disaster. Videos and drawings I've seen with the extra fire box to heat the chimney and initiate a draft, not to mention the ones using electric fans lead me to believe that people have attempted to address this issue, but I have never seen anything that solves it to my satisfaction. I don't believe anything other than a hot vertical chimney, by working with the laws of physics, rather than against can continue a safe draw as the fire dies out. Extracting most all of the heat and releasing just cool smoke sounds great, I just don't believe it works.

The facts as I understand them are that hot air/gasses are lighter than cool air, so they naturally move vertically, not horizontally, and I don't know of anything other than the extra little fire box or an electric fan can change that and both of those are subject to failure. It's just my opinion that it creates an unsafe situation. I would love to be proved wrong on that because saving every bit of heat in the house rather than using some of it to exhaust the gasses would be pretty sweet.  

I don't know when someone writes about a rocket mass heater which thing they are talking about. If it's first one, I think that's great, if the second one, not so much.

I don't know what a rocket mass heater is. In some photos/videos I see basically a small fire box and a vertical chimney, with a good amount of masonry material to absorb and hold heat.  The idea being a small hot fire with the heat being stored to be slowly released in the house. That makes a lot of sense and is basically the same idea as what used to be called a Russian fireplace. The small hot fires as opposed to big smoldering ones, release far less smoke and are much safer because it doesn't build up creosote in the chimney. Also, better because the nice hot fire and chimney are more resistant to a back draft.

In other photos/videos I see old metal barrels that might be fine for burning trash outside, but I would never have such a thing in my house. Also, often times with elaborate constructions apparently designed to make hot gasses move horizontally, rather than vertically. Some of those are very nicely constructed with nice ascetics but still it violates the laws of nature to move hot gas horizontally. I've seen discussions and images of using fans to help the flow and small secondary fire chambers to heat the upper part before a fire can even be started in the primary burn chamber and I haven't seen any creditable indication that moving hot gas horizontally without some extra forces applied is possible.  An electrically assisted draft and preheating a chimney are not in my opinion effective and worse, quite unsafe.

I think the first example where a small hot fire heats a thermal mass is a good way to go and is basically what I have now except it consists of a small Vermont Castings stove with heat shields removed, placed in a brick surround on a brick on concrete floor. I build a small hot fire in the evening and usually let it go out at bedtime. It works very well. If I was to build a new house I might go with something even more like the traditional Russian fireplace maybe even with some baffles in the chimney to extract more heat but not anything that would significantly restrict the upward draft and absolutely no heated benches.

Basically, I just don't believe a lot of the documentation on the effectiveness and safety of some rocket mass heaters.

I would like to expand my water/fish/plant habit, but I'm pretty set on only things that are happy in cold water. If I have to mess with regulating temperature it would be to cool it in summer rather than heating in winter. I mentioned but haven't yet experimented with freshwater clams. I've read that there used to be 300 species in the Ohio River, now there are just two or three and they are all small and mostly non-native, but I know of some tributaries that still have some of the much larger native species. They do not taste very good, but I wonder if that is like with the carp, living in polluted water yields bad flavor.

I do have space for a much larger pond but haven't had the time and finances to put it together, and still, there is the issue of needing an electric pump. I've experimented a little bit with white cloud minnows, Endler guppies and Japanese rice fish as well as our native creek minnows.  They have all survived "normal" winter when the ice is thin and intermittent but only the rice fish and natives have made it when the ice is thicker and longer lasting. I think they might do better in a bigger deeper pond where there is still three or four feet of open water under the ice instead of just one. I think with a bigger volume of water and a bigger breeding population any of them might adapt to my weather conditions.

I also love Paradise fish and think they might have a shot at adapting to such a set up.  Black banded sunfish are really cool little critters, sort of a miniature bluegill and completely hardy. I had some of the sunfish in my indoor aquarium, but they got too big and they ate their babies, so I put them outside. They lived there three or four years before a great blue heron came down one morning and ate them. Same thing happened to my baby snapping turtle.

The easiest for me are walking onions, they just grow, you don't have to do much of anything, but the flavor is horribly overpowering. I have them from three different sources, and they are all the same. I compensate by using just a small amount, which works basically just as a seasoning but still no good to actually eat them. I'm going to try the soaking in water method and see if it helps. To use just as an onion seasoning it works best to slice them very thin and dry them in the sun. Dried like that they take on a nice mild sweet flavor. Dried over a smoky fire like you would if making jerky is also very good.

I was thinking of bluegill in the upper basin for cold hardiness and low maintenance (and because they are readily available in the pond), but the yields seem like they would be pretty low relative to tilapia.  But tilapia would require a lot more management.

What would you in my situation?

I'm not sure what your goal is, mine would be largely aesthetic, just to create and enjoy a bit of a natural environment. I'm also very interested in food production but mostly as a moderate supplement to our meals and mostly seasonally. Although in a set up the size of yours and in your climate much more might be possible. A restriction there is the topography of your pools. If they are close together with the eight-foot fall in steep sections rather than in a gentle stream or shallow pool it wouldn't be as easy to grow the necessary plants to keep it all clean and you might need some kind of artificial filter.

That said, I would go with the bluegill for sure. Also, probably striped bass maybe of the hybrid type, crappie and catfish. Lots of other things might also work like crawfish, freshwater shrimp and for sure freshwater clams. Things like frogs might and water snakes might move in on their own. I definitely would not screw with tilapia or anything else that is picky about warm water. Just adds an unnecessary unnatural aspect and as a rule I think the colder the water it came from the better any fish tastes. O' I forgot about carp. They are nasty fish that taste awful, but I wonder if that is mostly because of where they live. In a nice clean environment that might not be true. They grow fast and they have lots of fish oil which is supposed to be good for up. I would definitely experiment with carp and if it worked out, I'd call it hillbilly salmon.  

For plants you have to have lots of them to clean the water and maybe to eat. Mint for sure, it makes masses of filtering roots. Hornwort grows super-fast, cleans the water and can be harvested for fertilizer in the garden. Waterlilies of course because they are pretty. Lotus for sure, pretty and I've heard you can eat them. Edge plants too, like cattails and cannas. I might experiment with things like rice too.

There isn't anything complicated about playing with water, it doesn't require engineering or schematics at all unless a person wants to make it so. Only problem in a small scale set up such as we are talking the water has to be in circulation and the only way I know to do that is with electricity. The video of the fellow with the tubs shows things can thrive without pumps, but it looked like he was into raising tropical fish. I think that would be fun but, in my climate, they would freeze solid unless inside a greenhouse or something and that adds a whole bunch of engineering and schematics and expense.  

Sam Shade wrote:The complexity and engineering involved in aquaponics has thus far kept me at bay, but I have a couple set ups that keep bring me back to the concept.

First, I have about a half acre pond that is home to the usual assortment of freshwater fish, turtles and algae. My dad is nuts for building water features and so he built a sort of volcano shaped fountain/ pond along side it, using a pump to push water about 8 feet up and then cascade  down into a series of large basins (each of which probably hold about 800 gallons) before streaming back into the pond.

Thus I have some quasi aquaponics infrastructure already in place. I already grow water lotus in the lower basin but I would really like to add some fish to the upper basin. I get a few fish out of the big pond with a fishing rod,  but I can't shake the appeal of netting dinner out of the mini pond.

The problem is from everything I've read, tilapia is the most efficient fish to raise in a set up like this but I'm in zone 7b, which makes tilapia raising an annual prospect. So I'm on the hunt for an efficient variety that can overwinter in 7b.

The second tempting use  of aquaponics has been referenced several times in this thread - since I'm going to be using 200+ gallons of water as thermal mass when I put in my greenhouse,  why not get some dual use out of it? I intend to cultivate some water hyacinth if I can keep the greenhouse temperature up,  but it sounds be great to utilize more of the water than just the surface area of the openings of my 55 gallon barrels.

Sounds to me like you have a pretty sweet setup there already. A series of 800-gallon basins with moving water in a couple of zones warmer than mine. All kinds of things should be possible with that.

Kevin Feinstein II wrote:

I like aquaponics for the fish and the life-force that living water systems provide.

I also just like anything water, fish, plant related. I don't usually watch videos, but I peeked at the one you linked and ended up watching a bit of it and loved it! Whole different set up from me though mostly because he is apparently in a climate where it doesn't freeze in winter. Those tubs would freeze solid in my climate.

My outdoor (200 gallon) pond is about two feet deep and freezes as much as eight inches sometimes over winter, only the pump keeps a bit of open water running in the stream part. It attracts enormous amounts of birds in winter; way more than the feeders do. In early spring it does turn pea green, almost thick looking for about a week or so. My theory on that is rotted leaves, fish poop and stuff have accumulated over winter and release an explosion of nutrient when the weather warms up, mixed with more sunlight the algae also explode. Then the water lilies, hornwort and other plants wake up, and the water quickly goes perfectly clear. Left behind is a layer thick of green fur on all the surfaces, then the toads come and thousands of tadpoles eat most of that. Whatever that is also lives in my aquarium, but the Otocinclus Catfish keep it under control.

I agree with you on the "life-force", but I do think actual food might also be possible except I'm thinking of the fish, not vegetables. As far as not using pumps, in my climate the water volume would have to be much larger and deeper. I don't use filters in my little pond or in my indoor aquarium. The plants and biofilm take care of all of that. Our local fish species bass, bluegill and catfish always do well but I have to turn them loose when they overgrow it. I can't raise a quantity big enough to eat, just a few and they are more like pets.

I would have to have a greenhouse to do it, but I have thought more than once about putting together a set up similar in some ways to the fellow in the video.

Here is a little video of my pond.