Backyard Aquaponics
A place to discuss aquaponics

I have lost 6 trout in the last 8 hours. They seem to have lost all color. The nitrate and pH levels are balanced. There are multiple airrators in the water I even cycled some water out and put clean water in. Now I have no clue what it could possibly be? Any ideas.

Check your water temp. Nitrate isn't usually the problem, it's the nitrites and/or the ammonia. You may not even detect any now but you may have had a spike earlier. I'd give these a check and post along with the water temp and pH readings. If you notice any behavior changes post those as well.

If you have algae in the system and low carbonate hardness then the pH can swing quite a ways during the day.

I think the loss of color is pretty normal if they've been dead awhile. It's pretty tough to tell much unless you see them immediately after death. You might have a look for any wounds, fin condition, gill color, spots ... things like that, if you start noticing any others struggling. I really doubt that it's disease, it's more likely a physical parameter that's causing the problem.

Keep aerating and make sure that you don't have any dead fish on the bottom. If you aren't growing strawberries (they are salt sensitive) and haven't added salt, you might want to salt (NaCl (sodium chloride)) the water at 1 part per thousand - use salt that doesn't have iodine or anti-caking agents added. This helps against nitrite poisoning and also helps the fish with stress.

Hey thank for the response! My nitrate levels where a bit off but I have fixed that. I currently am down to the last two trout but they look decent. The dead all have the same I was healthy yesterday but now look like I have been dead for weeks look to them.

Do you mean nitrIte or nitrAte? Any other info?

I'm betting this is temperature related so if your water temp is pushing 74 or 75 F that's a bad sign.

Water temp is currently at 65 the last remaining trout is loving it . I had to use a chiller to lower the temps. I believe next year I'll go with a warmer water fish . And run trout in the winter time instead.