Backyard Aquaponics
A place to discuss aquaponics

Frank- the overflow I am planning IS the SLO. Is it suitable for an overflow? I am putting the top of the T below the top of the GB so I assume the water will flow into the top of the T and then out the overflow? The pipe going down to the bottom of the GB could get clogged with roots but the top of the overflow will be above the level of the gravel so I would think the water would rise until it reached the top of the T then spill into the bulkhead fitting and out into the FT. If the pump stopped working the water in the GB would also siphon down the tube from the pump into the GB, which will be big enough to hold all the water of the GB.

My DH has a hand pump that would work to pull solids off the bottom of the FT and put them on the GB so I suppose I can just resort to that.

I suppose if I suspend the pump at a level where it will still be underwater if the GB is full of water and ready to spill over, then it would never be out of water as long as I keep the system topped up to compensate for evaporation.

HB

+1, HB

frank

Ahhh... I see my problem, I actually want the GB to F & D but the SLO is just an overflow and won't drain the bed... because of the T. So do I need to put another hole in the bottom of the bed or lower side and put a loop siphon there or can I do a bunch of elbows and redesign it more like a no holes overflow but still put a T in somewhere so the overflow part still works? Or add a no holes overflow in addition to the SLO which will then act as a backup?

I see another trip to the plumbing store in my chaotic future...

HB

some overflow drains will drain a bed right to the(ir) bottom, others will only drain the bed to a certain level,
some will be self priming (bell siphons, loop siphons), some will have to be primed (the over the rim types)
to me it is quite obvious how they work, which means I am probably not explaining adequately

but if you want some explanation of a particular type, please shoot and I will do my best

frank

You will probably want to put a hole lower in the side of the bed or in the bottom of the bed just to make the whole siphon set up much easier.

I've never seen the uniseals at a hardware store (thought I've heard that other people have) but you can order them. I think I put the link in the post where I mentioned them. With plastic, you can often cut a hole (using the proper sized hole saw type drill bit) and if it is just the right size, screw a pvc fitting in with a little aquarium silicone and avoid the whole uniseal or bulkhead fitting thing. If you download the barrel ponics manual (for free) you can read up there about how he deals with fittings through barrels without much fuss.

as to the pump in the fish tank. You really do want it to suck up as much of the fish poo as possible but having it a little off the bottom so that the fish never are totally high and dry is also a good idea. With fish swimming around in the tank, solids often will get moved around and sucked up by the pump anyway. It will take a little tinkering to find the exact safe height at which to put the pump so that it will not run dry even when the bed is full of water and yet high enough so that the fish can't be pumped dry if something goes wrong.

Good luck

"some overflow drains will drain a bed right to the(ir) bottom...... but if you want some explanation of a particular type, please shoot and I will do my best"

frank

Frank- I'm trying to avoid holes in the bottom or low in the side of the GB, so I would very much appreciate hearing about overflows that will drain the bed to the bottom. I'm tempted by the no holes overflow with the venturi drain added but don't know if it will accomplish complete draining. But now I do have the bulkhead fitting installed for the overflow. I was wanting to glue the SLO pieces together, cpvc pipe and fittings, but then the threaded piece would no longer screw into the bulkhead fitting. I could assemble it glueing as I go but then I would be kind of stuck. I don't know that the pieces will stay together tightly enough without glueing, to try it out, maybe it doesn't matter if it is not siphoning anyway? Or I could start all over and try to set up the no holes overflow. I glued a trial pvc one together today and have to wait a day or two to try it out.

I do happen to be a scientist (biologist) so will experiment until I hopefully get it right before setting it all up.

Waiting, anticipating...

HB

on this drawing all drains except the ones indicated with CLIFT will drain any vessel to the(ir) bottom once they are primed
the ones indicated with autosiphon are self priming


frank

Thanks, Frank, for all the drawings. It would seem the design I am contemplating, top row far R, would work as an overflow but not an autosiphon, but the design bottom row 3rd from L that has an elbow instead of a T would function as an autosiphon, but leave me without a backup outlet. Tough choice. Is it possible to cap the T and uncap the T to get both? Ball valve? Or maybe have 2 holes at that level, one as an overflow and one as a siphon. The container I'm using has two 1/2" or less holes that leak on each side, where the handles attach, maybe they could be used as overflows in some way. My overflow hole is lower than these including the height of the T if used.

Tomorrow I will test the SLO (not glued) and also see if the bulkhead fitting leaks. If I used TCLynx's no holes outlet with the venturi drain, the SLO could still act like an outlet in case the NHO failed. But can it autosiphon or drain the bed completely? I don't know. It doesn't seem to be represented in your drawings. Since I want to drain the GB to the FT, but her NHO w/ VD is taking water from the FT to the
GB so she wouldn't want it drained, maybe the configuration would have to change. Puzzles, puzzles.

HB

TCLynx- Thanks for the advice. I guess I am of the impression the fish solids would clog up the pump filter? Are they hard on the pump? I used to suck the solids out of gravel on the bottom of fish tanks with a turkey baster and put it on houseplants. It was great fertilizer. Do any AP'ers use gravel on the bottom of the FT or just have them bare? I once had guppies, gravel, snails, and water plants, they all multiplied and I had a series of 1/2 gal /2 L jars that were all happily increasing. That was when we lived in a warmer climate, I couldn't suceed with an unheated fish bowl here. I didn't give goldfish a chance though, which is what I plan to do now until I work out the kinks in the system. I'm itching to get some plants growing, I hope soon. I just need to solve the overflow and siphoning problems.

HB

just combine TR2 with BR3, but do not join them in one pipe

frank

For the grow bed, you do not need to mess around with the SLO overflow. What you need for your grow bed is a simple overflow just in case your autosiphon clogs up some how. Those small holes you mentioned, if you can manage to screw some sort of fitting through them or make them bigger and do so should take care of that. You do want the "overflow" level to be higher than the outlet for the autosiphon since if the overflow starts letting water out before the siphon kicks in, you will probably not get the flood and drain effect wanted. You probably need the overflows and all drain plumbing to be bigger than the feed plumbing into the grow bed. If the pump can push more water to your grow bed than the drain plumbing can let out during a given time, you wind up with a mess to clean up.

As to gluing the PVC. I Have many parts of my systems where PVC is just pushed together and not glued, especially where the PVC is visible (so I will notice if it starts leaking) and where the pipe is not under any pressure. From the outlet of my pump, I glue things since the pressure from the pump can push unglued fittings apart.

For a no holes overflow, you definitely need to be able to pull it apart or have a duckbill suck tube installed for priming.

For the hole through the side of the bed, so long as the bin is relatively flat where the bulkhead fitting passes through it, you should be just fine with the fitting. So long as the hole is low enough in the bin that you can get the water a bit above the hole without wetting the top of the gravel, you should be able to use that hole for an auto siphon. The biggest issue with an auto siphon with the top of the siphon going trough the side of the bed like this is that you can't really adjust the siphon height the way you can with a loop siphon. Siphons are easier with the holes low on the grow bed or in the bottom. You can probably still make it work though.

Here is a picture of what I expect you may wind up doing with what you have been describing. At least it is what I would probably do.

I ran my plumbing test today, with a hose on the fittings on the outside of the GB the venturi effect kicked in and the overflow was keeping up with the pump. I decided to stop hijacking this thread and start a member's system page, so here is the link with the photo of the test.

viewtopic.php?f=18&t=4339

Thanks for your help!

HB