A friend of mine has asked me to take her husband's two fish, with his permission. I don't have them yet, so I am not 100% sure of the species or water parameters. I know he has been lax on water changes. I know there are 2 tetras, most likely red-eye, that have been alone in a 10 gallon.
1) If I put them in my QT tank with the water they come with, how slowly should I add clean water? Will the Prime in the clean water "clean" the old water and shock them?
2) Once through QT (30 days), they will be moving to my heavily planted 30 gallon community tank. I know these are schooling fish. My thought is that I should get at least 4 more. However, if they have been alone for 2 years, maybe they would not like buddies? I would need to make this choice quickly, because any additions would also need a 30 day QT.