i apologize in advance, not sure of the levels! Need to get a test kit. Just did a 25% water change and added the conditioner of course, all of the sudden the water is extremely cloudy today! Our black skirt tetras are hanging out at the top all day. Sending my hubby to check the levels at petsmart after work. I don't believe it's a bacterial bloom but I'm not sure. You cannot see a thing in the tank! 37 gallons, 8 black skirt tetras, 4 Cory catfish, 3 platys 25% water change yesterday Tank was started 3 months ago, occasional cloudy water but this is the worst I've seen it! Thanks in advance for the tips!