Goldfish sitting on bottom

Question
Hi Chris,

I have a new 10 g tank and one out of two comets still surviving.  I have been checking water quality every day, and changing 25% per your advice every other day. The water had a bit of ammonia for about a week (around .25 ppm)and yesterday was the first day that it tested 0. Everything else looks good.  Nitrites were 0, ph was 7.0 and there were no nitrates.  Still my goldfish spends most of his day sitting in a rock cave or at the bottom of the tank.  Yesterday evening he was quite active in the evening and swimming around all over, but he went back in the cave around 10:30 while the lights were still on, and stayed there.  Even during the day he stays there.  Is this a sign that something is wrong?  Is there anything else I can do other than changing his water?  The tank is not fully cycled yet.  Thanks for your help!

Answer
Hi Bela;

I would just keep doing the changes and watching the ammonia and nitrite levels. He may still be recovering from the stress and needs his rest. Watch them from a distance too to see if the other one chases him. Sometimes a male will chase other fish, especially if the chased is a girl. ! They really can't successfully breed in such a small tank, but a male can be relentless in the breeding season. Watch for injuries or signs of parasites too like spots, dots or lesions on the weaker fish.

At Your Service;
Chris Robbins