Backyard Aquaponics
A place to discuss aquaponics

I acquired three fiberglass kennel enclosures that are 35" deep, 35"wide and 54" in length, as well as a couple enclosures approx 31" cubed. For more than twenty years these containers were temporary homes to dogs and cats while their families played inside Disney World. It is funny that I plan to reuse them as fish tanks.

I have buried two of these larger kennels into my backyard's sandy soil. This I hope will provide better thermal stability as well as supporting the walls of the container (they flex a bit). These kennels together should provide me about 500 gallons for fish.

I decided to plumb these tanks together with a SLO using 11/2" (38mm) pipe and uniseals.

For grow beds I was planning to use pond liner from a pond at my previous homestead, but the material had become brittle due to heat and sun exposure.

So instead I have cut in half three of the 31" units.

I have nest both halfs together for better support and insulation and have place these three units into a PT wood frame (2x6's) sutting on top concrete blocks.

This arrangement is actually my third configuration. My first set-up involved the use of galvanized metal fence posts. Due to weight, that config was an epic failure with the frames sagging in the middle. Included is a pic of the bent frame.

I was pretty disheartened at first because alot of effort and time was invested. It took me a few months to find the energy to start over. As you can see I have.

We have all had those disheartening moments I am glad to see that you have resumed. That is also a fantastic upcycle job with those kennels

Thanks Ron! I need support to figure out my bell siphon issue. One of my beds is overflowing just a bit before the siphon starts. So I guess the problem is either that stand pipe or the bell is too long/high. Or could it be that the siphon is being affected by a slow drain since all three beds are using the same 1 1/2" drain pipe.

Lower your standpipe.

Okay i'll try that.

So I think it was a combination of factors that was causing the siphon issue. Reducing the stand pipe height helped, but there was another adjustment that was needed. On the far side of the drain pipe I currently have an elbow with a pipe pointed up with a threaded cap. Somewhere along the line the cap was removed. Once I replaced the cap the siphon started quicker.

Encouraged by these findings, with a conclusion to the mystery of why my fish tank had nearly drained itself overnight, I continued to watch as two grow beds filled to the top almost simultaneously. With both beds currently sharing the same pipe, it seemed that the siphons could not start to drain at the same time. Instead the nearest to the exit side started to drain and then only once that bed was finished did the second start its siphon.

So in a matter of a couple minutes, I had figured out how to make this set-up work. I will have to add separate pipes to allow each bed to independently. Or alternately I will have to install an indexing valve to ensure that only one bed fills to the stop at any given time. It seems the first solution is the best even though it means I'll have to deal the clutter of more drain pipes.

That is unless one of you have any suggestions. Thanks in advance for any feedback or ideas.

Yea thats the problem with common drains unfortunately. What is happening is the bed closest to the drain out let or sump tank has the shortest distant to drain so it will begin first as you have witnessed, while it is draining it is causing a resistance in the drain therefore basically blocking the next one in line from draining.

The best option is to run seperate drains.

Cool, thank you both for confirming my suspicions. Should I keep them as
1 1/2" pipe?

Absolutely.

Single pipes to each GB, 1 1/2" will be perfect.

A common drain is not always a problem. Just depends on how you size it.

For my system I run a 25mm (~1 inch) pipe out of the grow bed siphon, and that dumps into a 90mm (~3.5 inch) drain line which them runs back to the sump. All 4 grow beds can drain at once and its not a problem.

Thanks Sam. At one point I did have all three GBs draining into a 4"
(100mm) common drain. It didn't drain fast enough because each of the 1 1/2 pipes was not fitted onto the larger pipe instead they just drained into holes into oversized holes. I'm thinking this cause a loss of suction.

With your set-up, did you use pvc fittings onto the larger pipe?

No I just have short pipes from the siphons to the drain pipe, and then they just free-flow into the drain pipe (its not sealed).

Something like this


By having the elbows, it provides just enough back pressure to help the siphon start. By the time the water is exiting the 25mm pipe, the water flow is self sustaining (until the siphon breaks).

I guess having that back pressure created by the use of elbows is the key. I have time today to work on it, I'll let you know.

I have decided to dig the second fish tank a foot deeper into the ground tomorrow. Currently the top of that tank is about 20" higher than its twin.

This effort will increase the distance of the vertical drain pipes and eliminate the current trip hazard of the horizontal pipe being 10" above the ground.

With the time change tomorrow I get another hour to break my back. Yipee!