Backyard Aquaponics
A place to discuss aquaponics

I think I prefer the first option HD, because the solids get to where they are most needed - the plants - instead of clogging up pipework. I want to go FISH TANK through VENTURI DRAIN to GROWBEDS through SIPHON to SUMP and PUMPED back to FISH TANK. How's that sound to you? I am still designing so no actual experience yet.

Actually, this would be for a small aquarium system. Growbed above fish tank siphoning into fish tank, fish tank over sump with overflow into sump. Sump on bottom w/ pump that pumped back up into growbed.

I favor the idea of Fish tank to grow beds to sump pump then pump back up to fish tank.
I like it mainly because the grow beds will help keep the sump cleaner. However, there are often situations of space ext that could make that difficult and it just means you might have to clean the sump tank out occasionally.

Then here are some other options that could make it even more crazy.

Grow beds (or troughs or DWC or strawberry towers) above tank draining direct or by siphon or whatever into tank, fish tank by venturi drain to more grow beds that drain by whatever means into, sump tank where the pump sends it back up to whatever you have above the fish tank. See lots of people like the idea of doing DWC or NFT troughs or strawberry towers but all those things need the water to have already gone through some filtration, this way it already has through the grow beds right after the fish tank and can now be pumped up to whatever alternative methods for growing you wish to try (without neeeding an extra pump or special bio filter since you already have regular grow beds going.

Hmmmm.... More to comtemplate.

If it is a small system, there is no need for a sump....put the GB above the fish tank and pump to GB, siphon then returns to fish tank (this is how I had system I setup)

What a neat idea! From sump to strawberry towers over the water.... Hmmmm.... got me thinking again.... good way to increase plant to fish water ratio......I am beginning to wonder if I will ever finish this design! What does DWC and NFT stand for? Why would a strawberry tower need the initial GB filtration first? I was wondering if there would be enough nutrients left for the tower.

Found it! Jamee put up FORUM USE ACRONYMS...

DWC
Deep Water Culture - a hydroponic method of growing plants in which the roots are suspended above, and allowed to drop down into an aerated nutrient solution. This is not natural but with a properly aerated solution the roots can be continually submerged without problems because the roots take up nutrients in the presence of oxygen. The solution is usually aerated constantly by using standard aquarium pumps and air stones, which deliver oxygen to the roots. The container holding the roots and aerated nutrient solution must be completely light proof in order to prevent algae growth. The solution must be topped off from time to time.

NFT
Nutrient Film Technique - In this method, the plants grow through light-proof plastic films placed over shallow, gently sloping channels. A steady flow of nutrients is maintained along the channel, and the roots grow into dense mats, with a thin film of nutrient passing over them (hence the name of the technique). A downside of the technique is that it has very little buffering against interruptions in the flow e.g. power outages, but overall, it is probably one of the more productive techniques.

Thanks Jaymee! Superb info everywhere!

TCL, why would strawberry towers need that first filtration through teh GB's?

...to keep the fish poo/pellets out of the towers and stop clogging

Another quesion: Can this set up use a continuously running pump or is a timer needed to switch it on and off? Could the loop siphon not drain so quickly - nice and wide flexible piping - that it empties for long enough to get oxygen to the roots before it fills up? Depth of GB's could aid with this. It would take longer to fill up to the height of root growth. Am I way off base here, or is this practically sound? I would prefer a continuous pump to run as wear and tear is less than on stop and start.

And another: In a power failure what would happen to my plants? It seems to me that the GB's would finish draining cos of the loop siphon but without power it would not fill again until power was restored - so I was wondering how long plants can go in just air - besides the obvious need for water each day. Could they go for a weekend if I was away and didn't know? Or at least overnight till I got to sort it manually. I thought a stop valve at the beginning of each loop siphon pipe could be closed in the morning.... buckets of water dumped on the growbeds straight from the fish raceway... and after say 15 minutes.... open all valves again. Perhaps repeat again at night if power still out... How practical is my thinking in the real?

Makes sense cos of smaller growth volume. Would plant growth then not be a bit straggly due to a lack of nutrients? Do towers work in this system? Maybe only certain plants?

...its not so much the plants, but would the fish survive without the O2 - plants should last at least a day without receiving an F&D, the gravel would remain wet and normally there is an inch or so of water left in the bottom of the GBs after a drain


I haven't got any towers, so not up with how they run...normally they are an extra to the system and water just trickles down the inside rather than F&D

I have tilapia EKB and have nothing to give them oxygen where they are now. Just in an old reservoir till I get this system set-up. I think tilapia are very tolerant of low DO levels. Thanks for the info on the plants. We have had power outs for a few hours at a time so it seems it is not too threatening to the plants. We did once have no power on the farm for days till the electical supplier came out to fix their hardware. Probably a back-up generator might be an idea when I can afford it just for the pump in such an emergency.

Some car batteries and an inverter are good power backup

Neat idea. Thanks OBO. Will look into it.