How to build a small commercial DWC aquaponics system on a shoestring – For less than $1700

henri pereira says:

thanks, never tried that, so will give it a try

Sustainable Jake says:

Add a venturi

Fish R Relaxing says:

Not true.. a 90 is a 90 either way giving the same limitations to flow. However drilling a small hole in the top of the bend will allow all air to escape and get higher flow cause the pipe won’t be trapping air restricting syphon would actually be better unless you submerge the t and add stand pipe to it. In that case you would get the exact same flow from either setup. If you want to increase flow you need to get a full syphon which for some reason aquaponics is scared of. To prevent it from draining the entire tank in event of pump failure you add a hole just under the water line so it will break suction once water drops how ever far you are comfortable with and sump able to hold. You can actually get more flow from a full syphon 3/4” pipe then most are getting from the standard t fitting type setup using 3-4” pipe. If you want to do it right imop for aquaponics Systems 1-1/2” pipe using the t setup submerged 12” under the water to increase hydrostatic pressure on the system and using a 13-14” stand pipe off the top of that tee to reestablish syphon when power returns with a gate valve on the pipe to dial in the flow how you want would be the best setup. Then drill a 1/2”-5/8” hole in the stand pipe 2” below water level to prevent syphoning 12” of water during power failure. You can achieve over 2000gph and close to 3000 flow this way getting much better solids suction out of the tank cause of the full syphon then tune the valve to the flow the rest of your system can handle. You can run pipe much further and have a much cleaner, more efficient and cheaper setup this way cause you’re buying much smaller pipe. Ideally size the pump to 1 or 3/4” return lines and depending on head pressure you can have 1650gph easy in return with the ability to intake much more. This prolongs the life of the pump itself as no restrictions are place on the pump itself.

This is how we setup sump systems in regular fish tanks. 1” returns with 1-1/2” intakes using full syphon. We setup the system to only have the sump relieve at best 10g of water in event of failure and at same time we baffle the sump so the pump can only add 10g at best to the tank in event of a clogged intake line.

Tune the intake to the return needed for balanced flow and eliminate all additional pump pressure on the systems. With this common setup we turnover water 10x per hour wo breaking a sweat. Higher turnover yields more dissolved oxygen and a cleaner overall system. Then you can increase pipe size and decrease pipe size where desired in the plumbing to reduce flow pressure or increase it wo altering the actual flow and water turnover of the system.. for example you wouldn’t want to blast a flood and drain media bed with high pressure from 1600gph flow rates.. so increase pipe right before the bed to 2-3” and use an elongated spray bar this would yield close to the desired water pressure into that bed wo sacrificing overall flow. Then use the same 1-1/2” pipe in continuous flow syphon from that bed. This whole belll syphon thing makes no sense. Out planted tanks have plants underwater entirely and indefinitely. They grow just fine and very fast. We add co2injectiin simply cause water doses have the same capacity air does. End result there is more then enough o2 in the water with a proper setup so roots don’t need to be out of water. I’ve actually seen several recent tests indicating this as well. Flow and turnover is much more important . In a dwc system intake on the bottom and return on the top. With 3/4”pipe. This ldnkeep from blowing raft all over wo sacrificing flow which deliver nutrient faster at lower more usable levels. Towers would be tricky and need a bleed off return sending most of the flow in a loop back to the sump while only 25% or so went to the tower. I would personally split this off the dwc return line which would lessen flow to both systems at same time wo adding additional plumbing.

As for filtration.. the higher the flow the faster you break down trapped solids.. eliminating the need for a mineralization tank. (Erosion in plain terms) last note coming from a fish keeper… one thing that drives me nuts more then everything else.. using clay media that costs a fortune in grow beds is very inefficient. Place the media in your filtration which holds much less media will actually yield the exact same results for minerals and most important benefit of Clay.. iron.. pull 25% out every 6 months and replace it with new media. This will give much better mineralization to the system and make much better use of the surface area for growing bacteria. We do the same thing in fish keeping only we use the clay media as the substrate at the bottom inside the tank. It both absorbs and stores nutrients not needed til the are while also supplying much needed iron. (Clay has high iron content naturally)

I also understand some like to try and keep flow limited for supposed better filtration.. this is true physically but practically it’s nonsense.. what is referred to in aquaponics as “retention time” in a filter is referred to by the rest of the water filtration world to include water treatment plants as “dwell time” the problem In small closed loop system is dwell time for filtration doesn’t work. The rules of biology and physics dictate that it takes 1 cubic foot of media at 1gpm flow to achieve a best case one pass filtration of 92-93%. This is cause filtration is limited by half life meaning no matter how many cubic feet or how slow the water moved through the filter you can not physically reach 100% single pass filtration of water. To make up for this you increase flow. The corresponding lines between flow and dwell dictate that it’s more effective to move water through a little media many many times then it is to move it slowly through a lot of media a couple times. In a 24h period you essentially achieve the same end result however you have massive spiking of toxins from the slower flow. When flowing faster and achieving a lesser % of filtration but filtering the same amount over said time you reduce spikes and achieve constant numbers…. in lame terms again your fish don’t all poop at the exact same time everyday.. it’s spread out over the entire day so getting rid of a little bit very fast is more effective then trying to deal with a lot all at once..

MyAquaponics says:

No difficulties at all, though we would not use an airlift pump for water re-circulation for this size system as its a little under powered. Does its job though, but would prefer higher flow. 25 Kg of fish used with 1000 litre tank. Recommend 2000-3000l tank for this many grow beds, and around 60Kg of fish biomass

MyAquaponics says:

Hi Abdul, keep in mind that this system was designed as a show case only and to prove that one can build an aquaponics system for low cost. The design is not fully optimized. Based on the the 12 square metres of grow beds, we should have a 3000 litre tank (which would not add much to the cost, but we had space constraints). Tank should be stocked with around 20 Kg of fish per 1000 litres (you can push it to 30Kg/1000l with enough aeration). Rate of feeding for the fish for leafy type plants, would then be roughly 40 grams per square metre of grow bed. Total of 480 grams of 30% protein fish feed per day. Since we only installed a tank that was just over 1000 litres, we also supplemented with some nutrients such as calcium and potassium carbonate. Lettuce in our system takes about 4 weeks from seedling to harvest in summer and 6 weeks in winter. We keep nitrate levels at over 100ppm with the help of beneficial bacteria and of course the supplemented nutrients. All fish waste is drained from the filter and put in an off system mineralizer and then fed back into the system as the organic matter gets fixed by the heterotrophic bacteria .

MyAquaponics says:

thanks, at the time the video was taken we had some tilapia fingerlings in the tank and in the growbeds.. It was low stocking densities at the time, so we relied on teh splash from the inlet to create the aeration. We have since added one 50mm round airstone. For the airpump sump, we used a 110mm plastic pipe and glued an end cap to the bottom of it. The pipe goes down into the ground around 1.3m deep (as we are pumping 1.3m high).. With airpump its best on a 1:1 ratio, i.e blow air 1m down to lift im up.