Problems getting siphon to start

Well, the longer I've had my system in place (set it up this past spring), the more frequently I find that my siphon won't kick in at all once the grow bed fills with water. Some days it will do several cycles just fine, but then I go check on it in the morning to find water standing in the grow bed, and my sump tank near empty with the aquarium pump sucking air.

I built my bell siphon exactly as described in the Web4Deb/Bigelow Brook Farm tutorials on YouTube, including the trap underneath the grow bed, so I haven't got a clue why the siphoning doesn't start.

Any suggestions would be greatly appreciated.

Guess it's good I only have goldfish at this point - they seem to handle the infrequent cycling pretty well. But that means I likely won't get to actually start introducing food fish breeds next spring as I don't know how hardy they well be.

The two things I would check first are:

1- make sure that the seal around the snorkel and the top of the bell are still intact and not leaking air.

2- Make sure that gravel isn't interfering with the operation of the siphon.

Thanks, Joseph. I know gravel isn't the problem as I have the media barrier in place and no gravel is inside of it. I will check the bell again to be sure nothing has come loose, though I'm pretty sure it's all tight.

Actually, I made two bells because I was originally going to hook 2 grow beds to my system, but I made the outflow from the fish tank too high so don't have enough water coming out of the tank to support two beds. I've alternated the bells in the grow bed that is part of the system, and have the same issue with both of them.

If anyone has any more ideas, I'd really appreciate it! Thanks!

Have you considered testing a U-siphon? I first had a modified bell and then a U-siphon and it has been slightly more reliable for me versus the bell. It leaves about 1/4 of the water in the grow medium, however that is a design flaw on my behalf.
In future set ups I will be going with the U-siphon for all my beds.

I know I didn't hit your exact topic on the head, however I always see people go right for the most popular set up rather than trying out others. The bell works awesome for some people and not so awesome for others.
I hope you can get the bell figured out better than I could, Good luck!

Thanks, Freddie. I had seen the U-siphon but thought it was going to be more involved to set up so had not tried it. I will check out some videos again on it and maybe give it a try. High winds destroyed the front of my greenhouse and I had to shut my system down for the rest of the winter as there was no way to keep any heat inside. Since I sort of have to start over in the spring, maybe this will help.

That is terrible! We are about to get hit with 2 feet here in Central Mass tonight into tomorrow. Candles, lighters, and monopoly are all ready to go!
I hope that next season luck will take a turn and your siphons work well! Do you have any plans for a reinforced greenhouse or a do you think you will go with the same materials and maintain the aquaponics there?

My greenhouse is one of those 10 x 12 Harbor Freight ones - aluminum and polycarbonate plastic panels. The doors were facing south and a previous storm had bent the track. I was using polyethylene plastic to insulate the green house - like a wrap - and that got blown off multiple times. Finally, another storm totally tore off part of the door track, which caused some panels over the door to blow away (one ceiling panel came off too). Most of the panels I'd screwed in, but a few I had not when I was just starting to put them in. I will go back and screw those in later. I have some ideas about building a new door way. I'm more upset that I foolishly left some fruit trees out in the greenhouse even after the first storm did some damage. One for sure is dead and I'm not sure I'll save the other three. (Have replacements on order, but that puts me another year behind in getting any fruit from them). I do want to restore the system since it otherwise was working well - plants grew well and the goldfish thrived. I want to get food fish this time (that was the point of this afterall!). Just a set-back. We'll keep trying.

Doing fruit tree start ups have been in the back of my mind for when I get a large enough property to homestead on. They sure do take a while to establish if you can't find a property with preexisting trees!
For the fish are you going with a trout? If a storm damages the greenhouse and it loses heat the tilapia can be a total loss. Trout are the opposite, they don't "do so hot" in the summer but are good for colder water!
Good job keeping positive through the adversity you are facing. First the aquaponics siphon, then the greenhouse and now the fruit tree's. That alone could change some people's minds about self sufficiency experiments. All a part of the crazy life!

I will go with trout or perch...I know it's too cold here for tilapia and, even if there were no problems with the greenhouse, I was only marginally supplementing the heat in there. I did try some catfish last year, but they all died. The first batch died within 24 hours and the hatchery gave me a refund, saying they had some trouble with that batch too. The next time it took about a week for them all to die. The gal at the hatchery thinks they just don't do well in tanks. As to the fruit trees, there's on sad little green apple tree that was on the property but it's never been pruned so the fruit is way small, and it has some sort of fungus or something. I'm going to try and get it pruned soon and then spray it in the spring. I planted another apple tree a couple years ago, so no fruit yet, but it's caught the same fungus. The stuff in the greenhouse should have been brought indoors sooner as they won't be out in the yard ever (lemon, lime, orange, banana). We'll see if the pomegranate and gingko trees transplant come spring. A late frost last year killed the other gingko I'd planted the previous fall, so I'm keeping this one in the greenhouse over winter for a little added protection during it's dormant time.

Trout have been wonderful for us here in NE TN. 70 cents a fingerling right nearby. Our cats did lousy as well but one has lasted for 3 yrs so who knows. I would guess it depends on your source. Trout are the best meal ever anyway and have proved very hardy. Start with 4" and up as the bigger they are the tougher they are in terms of die off. Also make sure your PH is right before you intro the little guys. Your bigger ones can look just fine but the babies can all die in the same water over night if too acid and mature AP systems will go acid. I use ashes from the GH wood stove to sweeten the water the day before and I place about half a cup at the fill side of each (5) grow bed.
As to bell siphons, I have now sold over 600 in all sizes and all over the world and I am here to tell you if your design is nice and simple you don't ever need no stnkn snorkel tube. You don't want any traps either. The 2-1 Bernoulli top funnel and 2 90's is all you need assuming you you make a nice clean and sealed bell. You can see all my designs at my FB page under Smoky Mountain Aquaponics. If you have basic tools you can make one easily. I have a bunch of tools all set for production now from 2 drill presses to belt sanders and chop saws and templates but I started with a saber saw and a chop saw. Personally I would start over with my simple design and you will be amazed. KISS always wins the race. Over 3 yrs online and never a problem if plumbed in correctly and that means an air gap or a vent right after the 2nd 90. Have fun. Jim

Thanks, Jim, I will be sure to check out your instructions. When I didn't have a trap, it seemed the siphon didn't work right either - I think it cut off too soon. I'm curious to see how yours differs from Web4Deb's design.

With mine if the bed didn't fill fast enough the siphon would just drain slowly. I turned up the water a little and they fire every time.

Hi Greg; the problem isn't a slow drain; it just doesn't start at all. I'm looking at a couple of other designs that are being posted on YouTube for siphons, so hopefully, I'll come up with one that works better than my bell. My grow bed fills by gravity from the fish tank, so I can't increase the in-flow as I never adjusted the valve I put in the line running to the bed - it's full open all the time. Thanks for checking out my thread and offering advice. I do appreciate all help!

Hello, Search you tube for "bell siphon 2.0" These have been a VAST improvement for our greenhouse system, start with low water flow, and are SUPER reliable. We used bell siphons in our grow beds prior to finding this idea, and switched over. Bell siphons are great, but at the same time can be really finicky, lol.

Thank you, Sokota...I will check it out. I'm not sure if I will get things running again this year or not - so many projects, so little time!

Hi Nancie,

I believe what is happening is that your sump tank water volume is too low to properly trigger your growbed siphon(s). When your sump runs low on water (usually from evaporation), your pump is only able to pump as water becomes available, so you end up with the pump almost sucking dry, pumping just enough to keep up with the water trickling from the siphon stand pipe. I believe simply adding more water to your system should address your problem.

Hi, Alex; Thanks for the reply. I don't quite see how the sump tank affects the starting of the siphon? The grow bed drains into the sump tank, sure, and the water from the sump is pumped to the fish tank, which then drains by gravity to the grow bed. The grow bed fills and then, more and more often, just never started the siphon. I have kept adding water to the sump tank as needed when the pump cycle causes there to be a lack of water going back to the fish tank, but that never has made the siphon just kick in when the water is already at or slightly above the level where it should start. If I am missing something here, please take me through it again? Thanks!

If you have a siphon that isn't triggering, then it usually means that water isn't flowing into your standpipe fast enough. In order for the siphoning action to start, your siphon needs to create an air-tight seal inside of your bell. Once your bell siphon starts filling with water, then the only place air can get into the siphon is through your standpipe (the part where the water drains out). The siphon actions starts once there is just enough water to completely block out all of the air, after which gravity carries the water down the pipe, creating a low pressure area inside the bell. If there isn't enough water spilling into your standpipe to create a temporarily air tight seal, then your siphon will just trickle at the rate water is coming into the growbed.

The real question is why isn't water coming into your standpipe fast enough to trigger the siphon? If your pump is sucking air like you mentioned, that means it ran out of water before your siphon was able to trigger. Air-sucking pumps usually are still pumping water, but at a much slower rate, certainly too slow to trigger your siphon. You need to make sure your pump has access to enough water to completely fill your growbed AND trigger the siphon before it starts sucking air.\

Are you running more than one grow bed?

I am only running one grow bed. There is no trickling of water out of the grow bed. It fills and sometimes the water is above the level of the top of the standpipe under the bell. I usually have to lift the bell slightly to trigger the siphon to start. When I first built the system, it worked fine...it took a couple months before this started happening.

I appreciate the advice and information. I'm not likely to get the system re-worked this season, but am glad to have a resource to refer back to. Thank you!

If you're water completely ran out, then your issue is definitely not having enough water volume in your system. Here's what you can do: let your system run dry again, turn your pump off, and then add 5 gallon buckets of water to your growbed (not the sump tank) until your siphon triggers. Once the siphon drains all of the water out of your growbed and into your sumptank, then add water to your sumptank until it is completely filled (might be best to do without fish, all the extra water might stress them out if it varies in pH too much). If, when you pour the buckets of water into your growbed, your siphon still doesn't trigger, then the problem is definitely with your siphon. In that case, you can post a few pictures here on the forum, or I can give you my email to send them to, and we'll take a look at your siphon construction.

Happy to help Bell siphons are pretty much my favorite part of the system; I've had mine working consistently for three years with no issues.

I have added water to both the grow bed and sump tank at various times. I guess I am not explaining my situation well. The grow bed fills with water yet the siphon does not start, does not trickle, and I can see the water level up through the gravel. I have to lift the bell to get the siphon to start. At those times, there is no need to add more water to the grow bed. I understand the part about if the sump tank runs low and if the grow bed were not filling, but that isn't the question I am trying to find an answer to.

I cannot be out with my system 24/7 to lift the bell every time the siphon does not kick in; some days, with my work schedule, I'm lucky to be able to check on it twice.

I looked for any photos I thought I took during the build process and don't have any good ones to share.

Anyway, I thank you for continuing to try and help me solve my problem...it's nice to have folks that are willing to take the time.

No, I think you're explaining it fine; I just wasn't sure i was

Another question, is your bell actually resting its weight on your standpipe? Since no water is trickling out of your standpipe, the bell cap could be making contact with the standpipe and blocking water from entering. There should be at least an inch or so between the top of your standpipe and the top of the inside of your bell.

There is at least an inch of space between the top of the standpipe and the top of the bell, but I may try shortening the standpipe a bit (whenever I get around to this project again), just to see if it helps and hopefully saves me from having to change it out for a whole new set-up. (I really don't want to have to move all that gravel from around the media barrier to install some other type of system!!)

Well, we'll make sure you don't need to build another one. Bell siphons are pretty easy to turn into timer based systems, simply get rid of your bell, drill some small holes in your standpipe (small enough that your pump can fill your bed faster than it drains), and figure out how long it takes to fill up. You can set it up to fill and drain once per hour.

The fact that you need to lift the bell to start your siphon interests me. Sometimes lifting the bell can cause the water in the bed to slosh around and provide enough water to trigger the siphon, (hence the recommendation to add more water) but like you said, I don't think lack of water is the problem. Since it isn't trickling out your standpipe, it sounds like water can't get into the bell at all....did you cut slots or drill holes in the bottom of your bell for the airbrake?

The construction pictures aren't too important, but a few pictures of your setup would probably help. A picture of the standpipe with the bell out, a separate picture of the bell, a picture of your growbed outflow, and a picture of the bell siphon all together could speak around 4,000 words Like I said, I can give you my email if that makes it easier to send pictures.

I still have to work again tonight, so will try to get some pictures tomorrow. There are "feet" to the bell that should be enough to allow water to get in. It worked fine when I first built everything as "The Better Bell Siphon" video instructed. Just, over time, took longer and longer to drain, then hardly drain at all.

Did you remove that filter sponge thing from your pump? Sometimes they get clogged with fish waste and other debris and slow your pump's flow rate way down. Since our pumps need to handle fish solids and whatnot, it's usually best to remove it.

I did not have a filter in the pump; when it had water to pump, the flow rate was always good. I'm working on some photos here in a minute.

This first image is just the trap/drain under the grow bed:


Next is the standpipe without the bell over it (haven't drained the grow bed from over the winter so you can't really see much):


This is the bell:


I took the standpipe out and set it next to the bell; there's about a quarter or half-inch of the standpipe that sets down into the drain; the bell gives plenty of head room at the top of the standpipe when they are in place:


The pieces aren't cut as neatly as you see on the video on YouTube, but I was using what saw I had (I think that guy used a table saw...don't have one of those). I don't think the quality of my cuts makes any difference.

Thanks, these pictures are quite helpful. One simple thing you could try is removing the "u" on your growbed drain and replace it with two 90 degree elbows with the last one facing down instead of up. This will help the water flow smoother down the standpipe, while still providing a little stop to help trigger the siphon.

https://www.dropbox.com/s/b5bk76csesoe10l/20150526_194543.jpg?dl=0

Thanks. I will try that, too, when I'm ready to get back to work on this thing.