cutthroat trout sick - pale help!!

[naturecentertrout]

Hello,
I have a coldwater tank with 3 cutthroat trout and 1 rainbow trout at the nature center where I work, they are about 3 years old. Today I came in after about a few days and one of the cutthroats is extremely pale, almost white. The conditions in the tank seem normal as do the rest of the trout.

Any ideas about what could be wrong, and how to deal with it? Any help would be very much appreciated - I am worried the poor guy is about to die!

Thanks!

[Lady Hobbs]

Have you checked the water for ammonia, nitrites, nitrates? I know you mentioned the water "seemed" ok but it takes a test to know for sure.

[mermaidwannabe]

How large is this tank? Trout usually inhabit rapidly-flowing streams and rivers, and also ponds (though mainly, they are stocked there). I would think it would require a huge aquarium to accommodate trout -- at least 100 gallons. For that many, more like 300 gallons. And good filtration and current. Riverbed-like substrate.

Do a water test and find out the chemistry. If those trout had been there three years, something has changed, or else they're beginning to finally succumb to stress.

-- mermaidwannabe