Silver Dollar

Question
They are a 2 year=2,1 years=2 and a 6 month old that died. I see them upside down, gasping. Test water it's good. Added an air line, doing little better some have righted them self, with the filter off. They live with 2 guppys and a plco.

Answer
Hi Kirk,
When fish are gasping for air, it means they are not getting enough oxygen.  Your filter must run, so that it splashes down water into the the tank.  There should be movement in the water.  Never fill your tank to the top, always leave a space so that the water from the filter will cause movement in the tank.  Let your filter run along with the air stone, so that they get enough oxygen.  Never shut down your filter, as this could cause your water chemistry to change, killing all of your fish.  Ammonia is the number one killer of fish, so my advice to you is do a 25% water change, and start your filter.  If you have anymore problems, please write back with more details, such as the size of your tank, the ammonia, nitrite, and nitrate levels, and the PH, so I can help you more.
I hope they get better.
Lynda