Backyard Aquaponics
A place to discuss aquaponics

I currently have an IBC system setup. Things were doing well for the first 5 months. When the heat came 100 plus degree days i notice that i started to see fish die off. Probably one or two a week. Starting with only 50 tilapia after a month i had 30 plus left. Since then i am down to my last 20. I constantly check the water which is perfect. The temperature ranges from 70 - 80 degrees. The only thing that comes to mind that is causing this is the used IBC tote which when i bought was told that it stored olive oil. Unsure of its use prior.

Want to know what type of fish tank i should use. Any information will be deeply appreciated.

Welcome kaneyeplay!

Tilapia should love those temperatures. Do you have an air pump to keep the aeration going? What media are you using and how much?

Thanks Dave.

I have an air pump that has 1 outlet in the sump, 2 in the ft and the last one is plugged. The media ( i hope your talking about growing media) i am using is hydroton 4 big bags of it. 13 in high by 48 x 40. I hope that is what you were asking.

The IBC should work as long as it was cleaned well and only had olive oil. The fact that you've been running it for 5 months makes me suspect something else is going on but I don't know what. Have any pictures of the system and fish, that might help. Where are the fish hanging out? Are they doing any flashing, like they are trying to scrape something off on the bottom?

Hi Scotty

I cleaned the IBC 3x to make sure it was as clean as i could get it. The fish are hanging around the top most of the time. They are doing the flashing on the bottom. Is that a bad sign? I have a mix of blue and gold tilapia ranging from half an inch to two and half inches.

Tilapia are funny, the flashing behavior is not always a tale tale sign. Sometimes they are eating the algae on the bottom. The feed I give them is a slow sinking pellet. When the food is on the bottom, it looks like flashing, but when the tank is clean, no flashing like behavior. What is your algae situation. Sometimes when an algal bloom dies off it sucks out the dissolved oxygen. That would be a likely candidate with the temps you are dealing with. It is hard enough to put oxygen in the water when it is warm, you don't need anything working against you.

But salt up just to be sure.

I was thinking like Dave and Ronmaggi that this might be lack of oxygen because less is available when the water is warm. I was also thinking that while the oxygen might be there, maybe they couldn't get enough because of gill flukes interfering or algae sucking it up at night or dying like Ronmaggi suggested and using it up because of this. Salt the tank as Ronmaggi suggested. If you have lots of live algae try reducing the feed and see if the Tilapia will take care of the problem. I'd also take a good look around the inside of the tank and see if their is a dead fish that you missed



Seen to be very small if you've had them 5 months - did you start with something else?

+1 I thought that sounded too small for 5 months as well. They grow super fast!

Aso when they are still small they can be cannibalistic.

Another possible outlier: spoiled/moldy food.