Hello all. Need some quick help here. I have a 70gallon tank with a bunch of live plants, 75gallon HOB filter, and these fish: 3 panda corys, 4 albino corys (1 about 2 years old, the others bought and introduced approx 3 days ago), 5 peppered corys ( 1- 3year old, 4 new additions added 3 days...