weird issues...

Question
hello. i have a 30 gallon tank and in it i have three 1.5" pearlscales and a 2"
black moor. all of these fish are acting strange. three of them are sitting at
the bottom of the tank, they are breathing but they aren't really moving. they
will kind of swim around for a second or two every few hours, but that's
pretty much it. the fourth fish is floating up to the top of the tank. he doesn't
have problems swimming down or getting around the tank, but when he
stops swimming he just floats up to the top of the tank. none of the fish look
like they are stressed, but their behavior is kind of freaking me out. any
advice?

Answer
That is too many fish for a 30g.  Goldfish need 20g minimum each no matter what size they are.  My guess is that your ammonia is high in your tank.  Get your water tested at your LFS and if ammonia, nitrates and nitrites are any higher then zero, change 50% of you water until the levels start to drop and then 25% a day until they are down to zero.  Then do a weekly water change of 25-30%.  You will continue to have problems with your water if you are overstocked.