I bought a couple of Zebra Danios today and they turned out to be infected with Ick. One has several white spots on its body and the other has a few. I made the huge mistake of not examining them closely at the shop. After acclimatization, I put them into my 25 gallon tank that houses several other community fish. Within a few minutes I noticed one of them was acting weird and only then I noticed they both were infected. I immediately removed them and moved them into my 7 gallon quarantine tank. I am medicating the quarantine tank, but my question is, should I treat the 25 gallon tank too? The fish have hardly been in that tank for less than five minutes. Since I live in India and summer is just about getting over, the tank's water is at 82 F. The quarantine tank is a degree higher because it is a closed tank. So is it necessary that I treat the main tank too. It houses 6 tetras, two small goldfish, a 3inch Koi, 2 1-inch Angels, one Pleco, one juvenile Yoyo Loach, and a few Danios (older ones - not from today's purchase). I have added four tablespoons of rock salt in the 25 gallon.