Yellowing/Greening Bleeding Heart Tetra & Large Eyes

[cee219]

I've had my five bleeding heart tetras in my 55 gallon (up for about 8 months) for about a month now with no problems. As of yesterday I've noticed that one of them is developing a bright peagreen/yellow grow and strip along the top of it's body, and another one is starting to turn from it's silver color to a bit of a darker color.

I also have one Bleeding Heart Tetra that isn't suffering from the above, but whose eyes are like... 3x bigger than the other four, like he's looking at me with a magnifying glass. Popeye?

I'm terrible at comparing the ammonia test strips, but I wouldn't put an ammonia problem past me as this is my first tank and have had that problem a few times. Nitrites are at 0 though. Any suggestions, especially on what is making me tetras turn yellow would be helpful!

 

[TCTFish]

Have the tank water tested thoroughly for ammonia, nitrite, nitrate and pH. Post results (numbers please).

What type of filter?

A changing of pigment is either a response to reproduction or stress. Being one is showing signs of a disease (popeye), I'd suspect stress and probably due to water quality. Pay particular attention to nitrate results.

For now...the fish with the popeye should be placed in a QT and medicated for popeye.

For the main tank...start doing small but frequent water changes...about 10% to 15% twice a week for at least two weeks. Get the sample of tank water for testing prior to the water changes if possible. You can also use nitrate abosrbers in the filter and use Prime or Amquel Plus water conditioners (these are formulated to protect against any nitrite and nitrate in the tank). Cut back on feeding as well. Two minutes worth of food per day every two to three days at least until we know the test results. Most LFS will do the testing for you at no charge. I don't trust dip sticks. Liquid tests are more reliable.