Fresh Water Aquarium-Distress Tank

Question
Hi,

My fish all seem to be breathing rapidly.  A 65 Gallon tank, I have several discus, ghost knife, guppies, mollie and a ?pacasmus? (bottom fish).  None of them seem to have any problems with their gills but they are moving slowly and their mouths are rapidly moving.  Please let me know what you might recommend in troubleshooting. Thanks!

Answer
Hi Andrea,
It may have something to do with the fact that these fish are all incompatible.
Discus are actually a kind of Cichlid, and should not be housed with guppies and mollies, especially since eventually it may decide to eat them later on, but also since most Cichlids require much more alkaline water than other tropical fish.
Mollies prefer brackish water, while guppies live in freshwater, and neither should be living with a ghost knife.
It could simply be that all of your fish are stressed out.
You should either return a few, or start working on separating them into appropriate tanks.
The Discus should be in one by itself, and later on you may add other Cichlids with the same water requirements. The Ghost Knife should go into a semi-aggressive tank and can probably be housed with your bottom feeder, and the guppies and mollies can go into a tank of their own - and you should add aquarium salt to all of them to reduce stress, replace their slime coats, and add electrolytes to the water.
That being said, you might also need to test your water quality to see if there is a high level of ammonia. When there is too much ammonia in the water, it tends to suffocate the fish, which sounds like that may also be the problem.
Even if you can't test your water, I recommend doing a few small water changes at least every other day (25%) for a week. And then a 25% water change once a week from then on.
I am sorry to be the bearer of bad news, but it really will be best for your fish to separate them all, and I don't want them to suffer, or for you to be disappointed. Best of wishes.