Backyard Aquaponics
A place to discuss aquaponics

Hey Folks, after puttering for a while with some failed smaller systems, here's what I made. The fish pond is 110 gals. The grow beds are probably 15 gal each. I used a combination of gray gravel and red cinder. It is a flood and drain system. I have a 700 gph pump that runs 15 mins to every hour 18 hours a day. The GB fill and then drain slowly through a succession of dril holes in the drain pipe.

I have about 6 koi and 4 tilapia and 2 crayfish. I have cycled for about a month and now have added various vegetable seedlings.

I have put up a shade cloth because in my previous system the vegetables kept bolting, I think because of too much sun(guessing here).

I have not yet tested the nutrients however the pH level is around 7.

I have one question. Very little water sits in the GB when pump is off. Is there enough time for the bacteria to convert nutrients if it happens only during pumping?

Please give me feedback. Any improvements you guys see I can make?

Eventually I plan to add more fish and another GB.

Thanks
HN

more pics

Looks great! How do you time your pump? Is it a float switch, or straight timer?

digital timer. I can set 14 switches

Nice

My primary concern would be the ratio of fish tank to grow bed. 110 to 30 gallons is about 3.5:1 and a little reversed to the normal aquaponics ratios of 1:2 or more. But with a light fish load, it may be ok. You may want to add a separate biofilter.

Just so I am clear, you are suggesting that I need more gorw bed medium?

H, (gee i'm lazy )

The system look like it will work fine to me, you are running flood and drain which is good. There is plenty of space for the actual BACTERIA.

Stock the tank to the limit of the volume of the grow beds as you will have reduced solids capability and plants for nitrate uptake. With out going back over the figures it looks like it will handle the fish you have just fine.

What a great job! If you have more containers that you could make some more growbeds, that might be better, but I guess that depends on whether you want more fish. (Oh wait, tilapia. You're getting more fish whether you want them! ) The current growbeds look sufficient to support current fish and maybe a bit more.

As long as the grow media remains moist, the bacteria will be fine, but they only get a chance to catch a meal of ammonia/nitrite when they are in the water. My system is also flood and drain.

You might care to get a Master Test Kit so you can measure ammonia, nitrite and nitrate and see for yourself that the bacteria is doing its job. It's hard to understand all that when there is nothing to actually see. Kinda like magic!

Hi HN, I'm with rassd, plan for a lot more grow bed volume. That will be the limit on what you can achieve (the tilapia will breed easily). I am coming at this realization late - I think the natural tendency is to worry about the fish water volume more than the grow bed volume and then it is a pain to play catch up.

Alright, thanks guys. I will plan on making more grow bed space. Yeah the tilapia breed like mad. IN fact I think I have 2 pregnant ones. The babies get eaten pretty fast though.

One question. If I do add more growbed space how do you guys suggest I manage the water. What I mean is if I add a third and fourth bed then thats a lot of water being pumped out of the fish. Add a sump? any suggestions?

HN

To manage that you can use a sump so that the fish tank volume is constant, and the sump volume goes up and down. You can do this with either fish->bed->sump->pump overflow or fish->sump->pump->bed overflow. I am using a fish->sump->bed configuration in my system, with siphons in the beds to make them flood and drain. Another thing that may help is if you use several beds with autosiphons, then most of the time each bed is only partially filled. It is rare that they all are completely full at the same time, so on average you would lose 1/2 the grow bed water volume out of your fish tank.

I live in hawaii and finding supplies is difficult. Can anyone think of what kind of supply store I could get a large growbed? I want a rectangular GB about 50 or more gallons thats 12 inches deep. Any ideas?

Janet likes Rubbermaid 50 gallon stock tanks, where did you get the TuffStuff tub? Does the same place carry the 50 gallon Rubbermaid ones?