Welcome to the forum
Kserious
. Fair play to you for getting involved in the care of these fish. It's a shame your son doesn't share your sense of urgency!
As already mentioned, and also confirmed at petsmart, it looks like your parameters are far from ideal. Basically high waste output by the fish and lack of regular water changes/maintenance is the cause of this.
Get to grips with the regular maintenance aspect of the hobby and your situation will improve, though from a long term point of view, those fish either need a much bigger upgrade, especially the cat, or re-home them.
And take no notice of your son, come on here if you want good advice. Good luck.
This is basic stuff young man, you should have all this dialled in by now. You've been on here long enough, do you not pay attention, lol.