Backyard Aquaponics
A place to discuss aquaponics

Hello all, thank you in advance for reading and offering advise! I have a small aquaponics(indoor) system which I have built from rubber maids and the like. The main "tank" is 50 gallons with three tilapia (only one remaining as of this morning), system has been in operation for about 3 weeks and current measurements: 76 deg F, PH- 7.4, Ammonia- 0.25ppm, Nitrites-2.0, and Nitrates jumped to 80ppm last night. I have been doing my best to research before asking the same questions as have been asked before, but to no avail. The other issue I have had is eating, fish were not eating feed and would wait a couple days before throwing in another <10 pellets, but fish would only eat a couple at a time, the rest I would net out. ANY advise to save my sole survivor would be great, I hate to fail at things and this is one of those that ranks high on my list right now. Thank you in advace!

Hi Xander7, welcome to the forum. Sorry to hear about the fish.

First advice for you is to stop feeding. Second suggestion is to salt the water in the tank to 1part per thousand with uniodized salt the kind without caking agents. This helps the fish with building a slime coat, with stress, and with nitrite toxicity.

The jump in nitrate levels may be an indication that you had an ammonia or nitrite spike without knowing it. This could have killed your other fish and the survivor may not be long for the world if that's the case (may already have some damage). Hard to say for sure at this point what the cause is but since you are showing some ammonia and nitrite, let those levels come to zero before trying to feed again.

Sometimes it helps to aerate the tank really well.

Remember to remove any uneaten food.

Hope this helps.

Hello and thank you! I forgot to mention that nitrites were beginning to spike a day ago and salted 1g to 1L with sea salt. My last one just died about an hour ago despite my efforts to save him. Therefore, I would like to try again, but be better prepared. In your opinion, would you attempt to get levels to balance in what in current system for some time or just throw everything out and start from scratch? I am leaning toward nitrite poisoning with the lack of eating and the lethargy my fish were experiencing the last few days, however, I am far from an expert.

Sorry to hear about the fish - always tough to lose them... I agree with Scotty that it was probably a nitrite spike that killed them all. What sort of filtration and/or biofilter do you have for your system? How much water is in the entire system? And how old were the fish?

I am sure we can help get you back up and running in no time...

+1 with Scotty and ebeuerle above - in small systems the effects are often exaggerated because there is not much water volume to buffer changes.. so things can happen quickly. Quick is not so good for the fish.

given small system - did you have air running ?
was the system running 24/7 or on a timer

the system has probably cycled now given your numbers, keep it running and answer ebeuerle's question.
perhaps some pictures as well.

Need to know more about the system as mentioned because it might help to add filtration depending on what you have. It wouldn't be good to have a repeat if you can do something to prevent it. As far as the current water quality, more than likely the filter will take care of the current problems given a bit of time. It seems unlikely that it was a disease issue which could require a bit more caution.

Hello Eddie,

Total size for system was about 50-55 gallons. Filters used: 50 gallon on tank power filter and a swirl filter that I made out of tote at top of system. I had fish for almost four weeks, but were about 1.5 lbs when I got them.

Hello Darren,

System was running 24/7 with a good size air pump.

Hello Scotty,

Thanks again and I did take pictures of my last casualty just in case you spot something I missed in the disease department.

Was attempting to upload pictures and my phone will not reduce size to required 900x900pixels. Therefore, will have to find old camera and upload.

You can also resize using software on your computer. There are a couple of threads at the top of this page that might help - http://www.backyardaquaponics.com/forum/viewforum.php?f=4

Pictures of system and photo of last tilapia are uploaded. After reviewing the fish picture, I did notice some blotchy spots on the tips of fins. Do not know if this is something or not. Thanks in advance.

Looks more bacterial than fungal. Without knowing what it is and whether it was secondary to the nitrite and ammonia problems (which I suspect) tough to say what to do. I think if conditions get better whatever this is won't be an issue but you may want to let the tank sit without fish for a week or two, it's up to you. You can still add nutrients for the plants in some other form.

That sounds like a good plan. While it is sitting for a couple weeks, what would you recommend to use for natural fertilizer without causing issues with levels when fish are introduced? Also, any other suggestions for keeping the system healthy once a couple of new tilapia are introduced? Thanks again, you have been a great help.

Blood and Bone works if sprinkled on the grow beds and contains a lot of the same things as commercial fish food. Another possibility is a bit of vermicompost at the base of some of the plants. Basically you need something that gives a slow release of nitrogen but has other things as well. You could probably add some ground up fish food and do alright as well. When you're a few days from adding the fish just stop adding and make sure the ammonia and nitrites are zero before the fish are added.

There really isn't much filtration in your grow beds because there isn't a whole lot of depth to them. The amount of fish you can keep is very dependent on the filtration you have so you may want to revisit this. You may need to add some supplemental filtration. This thread is a start toward figuring that out - http://www.backyardaquaponics.com/forum/viewtopic.php?f=12&t=6646

Tilapia are a bit more tolerant than most fish but they still can have troubles if conditions aren't right.

Hope this helps

Scotty,

Thank you again for all your help, you are a wealth of knowledge! Hopefully, my next attempt will be a successful one and will be able to eventually grow to a larger system.

In small systems like yours it's very hard to keep control over the water chemistry. In a healthy aqouponic system your ph should always drop and not go up. This is paired with good design plants fish water and feed. In big systems the fluctuations are slower less frequent and more forgiving. You definitely have either dissolved oxygen problem or ammonia spike unless you added something in the line of chemical nutrients. My advice would be to build n bigger system. From my experience it's good to start small and work your way up to bigger and better unless you know what you doing. Don't give up.