Hi..I am new at this..My sister gave me a tank and a large goldfish...Don't know what sex it is...bought 3 more to put in with him...they are all doing well, but the one will sit on the bottom of the tank hidden...they had been chasing each other around....now, this one will come out every so often and swim around like it is ok, then it will go back in the plants and hide on the bottom of the tank...what is it doing there?Does anybody know? This one is a calico fantail...they all eat well and are all very active...except this one..Is it ok or should i be worried?

Hi Harley, and !
The one who is sitting on the bottom, is he the one who has been chased around the most?
Just to make sure that is all it is, can you give us some more info about your tank - how many gallon, how long running, what kind of filter, what are the ammonia/nitrite/nitrate/pH readings, how often do you do water changes?
I know its a lot to ask, but better safe than sorry!