Hi a friends 4 year old gold fish ,white with a little orange on back, is starting to change colour - the tips of fins are going blue.No change to diet. Any ideas what can be causing it?
Ahhh, ive just Googled it again. Apparently they change colour due to lack of light. That might explain it then...the bulb in my goldies tank went a few years ago, and as its a fiddly thing to get at i've not bothered replacing it.
I never had a bulb when I had fish. I had them near a window though, but then the tank would get all algae cos of the sunlight. This is why I never got any more :)