Backyard Aquaponics
A place to discuss aquaponics

So this is my system in my backyard. I am in southern Wisconsin, and after a cold spring I got a late start, not having fish until mid May (100 1-2" Tilapia). Unfortunately we got another cold spell, and low and behold, another 100 fish purchase. They sent me Fry instead of Fingerlings, so to make up for it the guy sent me 25 2-3" guys, which puts me at about 120 fish or so (couple have died, here and there, no rhyme or reason to my limited knowledge.

I have a 275g IBC, with an opening cut off the top, so it is about 250 gallons or so. The overflow pulls from the bottom and into a 50g barrel swirl filter, with a drain at the bottom to remove solids. Then the water goes to my DWC raft bed, which is about 4' x 7.5' and about 10" deep. From there the water hits the drain point, and returns to a barrel on its side which is my sump. The pump is in the sump, and leads up to a spreader bar over the tank to complete the loop. I have a heater for when it gets cold overnight, which I have not been using lately. Water temp is usually mid 70's or so, but during a stretch of warm weather last week it was into the 80's.

I am trying to do this on a budget, due to having a wife who is less than thrilled of this being in her backyard. Fish seem to be doing well, eating and growing a ton, so I don't think temperature is an issue to them.

It took a little longer to semi cycle, and I say semi cycle because for the last 6 weeks my Nitrites simply will not drop. I started with 30 goldfish to cycle, with 1 of them remaining (grew to about 4 inches or so). My ammonia spiked, Nitrites showed up, then dropped to near zero, so in went the Tilapia. Since then (8-10 weeks), my Ammonia has been steady at about .25, however the Nitrites are still showing 5.0, or higher as that is as high as my API test goes. Nitrates have been fluxuating between 20-40, and plant growth has been pitiful.

I have had issues getting anything to start from seed. I have tried direct seeding, germinating in a papertowel and moving to Hydroton in Net Pots once a tap root is there, all to no prevail. I have done a ton of reading online, especially this forum, and have tried many things. I have salted to prevent disease due to the high Nitrites, done water changes (10% or so almost daily, and 30% once a week or so). Fish seem to be doing well, they are coming to the top to eat, and do so frequently. The 2-3" ones I got are now pushing 5" about 6 weeks later. The 1/2" fry are mostly a solid 2-3", and again eating and growing a ton.

This is my first go at this, and next year will be going with flood and drain beds rather than the floating raft bed I have now, but hoping to be able to get something from someone who can help salvage this year. My wife is constantly ribbing me about how pathetic my plants look, and would love to be able to do something positive. I need to take some new pictures in the morning, as the ones I took tonight are about 7 times too big of files to upload. I do have plenty of aeration, with 2 stones in the FT, and another 3 bubble bars in the raft tank. I have them running off 2 separate air pumps to push even more air.

Any help anyone could offer would be greatly appreciated, and I thank everyone for all they have posted, it has been a huge motivator for this whole process (even if it does not appear I am much of a student lol )

Welcome Brian! The first thing that I have noticed is that you are WAAAAY overstocked. Find another home for at least half of the tilapia. You simply do not have enough biofilter space. Gravel growbeds are the traditional biofilter of choice for AP, but there are some other biofilter options. You need more surface area for the bacteria to colonize. It is challenging to get stuff to start from seed in ap. I have never really been successful at it. I have a soil based seed starter kit. It works well for me. Once the seedlings get large enough, I transplant them into the growbeds. It takes a little planing to get what I want when I want it, but is much easier for me.

That was one part I forgot to put in, yes I know I am a bit overstocked. I went a little heavy because I figured I would lose some as this is my first time through the process. Apparently I don't suck as much as I thought I was going to. I am thinking about starting to set up in the basement to prepare for winter, so some may get moved down there in the coming week or so. In the mean time, if a few die, then I guess that solves my problem a little.

I am trying just about every angle I can for the veggie's, thinking in Sept or so I will have better luck without the constant heat we have during the peak summer months. Either way, learning experience, and mistakes are the best form of that.

Amm and nitrite poisening caused by overstocking will effect all your fish... not just a few.

Well, haven't fed in a day and a half, temperatures have cooled down a little lowering the toxic level, and the Nitrites are now showing between .5 and 1, been a long time since the test has not been a super dark grape purple. Baby steps, hopefully my 3-4 month system is finally beginning to age a bit.