Sorry
I will answer every question to the best of my abilities. 1: The afflicted fish are goldfish. They look just fine, but they keep hovering at the bottom of the tank about a millimeter away from the surface, or even touching it.
I don't have the exact values for all of these, but Wednesday, when my LFS tested my water, all of parameters were good. (Such as: Ammonia: 0.00ppm, Nitrites 0.00ppm, Nitrates ???, temp is 80 degrees Fahrenheit, Ph ???) Like I said I don't know some of the exact levels. Might go back and have them test it again and give me exact numbers.
The tank is a 10 gallon tank, and has been set up for 2-3 weeks in the current... Session?
I have a Tetra 10I filter in it, and I think I am going to buy a second, or buy a 20 gallon filter, and use this one for something else.
I have 3 goldfish at about 1.5 to 3 inches long, 3 yellow lab cichlids that are about half to an inch long, 3 snails at a rather small size, 2 little angelfish ( they aren't babies, but they aren't adult size for sure ), and one pleco that is about an inch or two long. As I said before, I am trying to get my 29 gallon tank ready.
I did a water change last night (12 hours ago) of about 30% of the water. I do it every Friday for the same amount.
I have had the fish for about a week or so, and acclimated them for 20-30 minutes.
No new things in the tank.
I have been feeding them all Tetra tropical flakes. I have been using this for them since the beginning.