Backyard Aquaponics
A place to discuss aquaponics

Hey Forum Folks,
I am going to be stepping in to help my buddy manage a small aquaponic system which is currently using ~300 yellow perch and ~ 40 5 ft vertical towers growing lettuces, herbs, cucumber and tomatoes. The system is modeled after the Bright Agrotech system. Seen here


Now I'm no aquaponic grower but I have done a little work with these systems and have been successfully been farming the past several years so I figure this should be a do-able winter project.
I just looked at the system this evening and we did some N testing. We read 6 ppm NH4, ~0 ppm NO2 and ~140 ppm NO3 at a pH of ~6. They have been draining off water and replacing it with off-gassed room temperature water ever several days.

The plants look real sad in the system but they have been keeping it in a state of dormancy for some time now. I suspect there is a whole host of deficiencies and I will add several photos to show some classic symptoms for anyone whose a good ID. And if you have any recommendations for boosting those nutrients on the cheap that'd be real rad.

Plants are also super leggy and seem to be weak, flavorless and pale. In terms of lighting they are using T8s on 18 hour on cycles. Seedlings are under 34W F40CW lights on 20 hour/day. Is there a need for fanning seedling to harden them during infancy? The plants in the towers seem to have a hard time fighting the gravity vector and water has been seen running down them.

Any suggestions are welcomed. Any additional information can be provided upon request. Thanks for making citizen innovation great and functional yall. -m

not really experienced with indoor systems, but NH4 is way high, 300 fish is way to many!

are the towers BA units or home made, if so what media do they have? and is there 40 in that photo?

the deficiency could be Mg or Mn, maybe try some "seasol"

I'll agree with slowboat. Way overstocked, and I'm guessing the constant water changes you need to do are flushing away all the nutrients, hence the bad growth.

What filtration are you using?

Sorry Slowboat, let me clarify. Currently there are maybe ~20 that are growing anything. The idea is to eventually fill out the whole 'pod' with towers to equal ~40. Although we are considering columnar oyster mushroom bags between the plant towers where humidity is higher so it could be more like 30 towers.

The plant towers are home made out of plastic rectangular tubing. The slit is cut into the side and a bog restoration pad material made from a matrix of intertwined plastic fibers is folded over on itself to create a slit where seedlings can be secured.

To address the high NH4 levels I would like to install a mycofilter using straw or wood chips inoculated with Stopharia mushroom which have been shown to filter out soluble nitrogen sources like NH4, NO2, NO3. http://dungenessrivercenter.org/documen ... rt_000.pdf
However, I have not done all my homework and am unsure if the mycelium would prey on the nitrifying bacteria as well that keep the system going.
Filtration is being done by the media and any sediment that ends up at the bottom of the sump tank is vacuumed up to remove it with a wet-vac.

Since we are hoping to do some oyster mushrooms the humidity will need to be even higher (currently ~70%). Do you all have any suggestions on plants that tolerate humidity but have a high price point? I was thinking red amaranth, edible mallows, purslane, herbs, etc. It will also be interesting to think about maintaining humidity at such a high level.

May need to put mushroom columns in the center of the pod to insulate them. Hopefully there is a O2-CO2 exchange that happens!

So it sounds like I need to remove some fish and/or fill out the rest of the pod with plants. I will be starting this late October but in the mean time I can start getting seed together, planning, etc.

I will also have access to some free vermicomposting system, any suggestions on how to best use this in our system?