Hi, I'm after a bit of advice which I haven't been able to find out elsewhere...

I posted before that one of my 2 Whites has been hiding mostly in the waterfall I have in there. Well now both of them have started hiding there... It's been about a month or 2 for the first one and my other one has started doing it too.

I have been trying to keep an eye as best as I can on them. The tank is in a clean state, fresh water etc. but they still insist on hiding in the waterfall. If I put my hand in to feed or anything else they hide back in the waterfall. They do come out at night and have a roam around, but that seems to be it. They tend to be brown when they are in the waterfall...

Is there anything else I can do? Does it sound serious?

Thanks