Sick Boesemani Rainbow

Question
I have 5 Boesemani Rainbows and 1 appears to have taken ill.  It is a juvenile, so never had much color, but has turned white with a yellow tint.  He swims by himself and spends a lot of time near the top of the aquarium "shimmying" back and forth.  Any ideas?  Should I quarantine him?

Thanks!

Answer
Hi David,
My first thoughts are you should check the water quality. Make sure the ammonia and nitrites are both at 0 and nitrates are 20 or less. Shimmying type behavior is often related to water quality problems or the beginnings of an illness. Have you just recently gotten the rainbows? You may have unfortunately got a hold of a weak individual in your group.

Regardless, I would try doing a 30 percent water change and see how that helps. I still recommend getting your water tested as well just to be sure. Also make sure the temperature is not too cool. If the other fish are doing extremely well if I would believe that this is an individualized problem with this rainbow. Keep a close eye on him if he develops any type of illness symptoms i would definitely quarantine him.

Best of luck I hope this helps!!
Happy holidays!
Susan~