First, ich organisms are present in a tank all the time unless you are running a UV Sterilizer. It just needs a trigger such as stress to set it off. Your 60L has high nitrite and I assume ammonia too since you haven't tested it. That is the trigger it needed. Second, you need those test kits regardless of whether you do a cycle with or without fish. Actually, you need them even more with fish in the tank. If you put fish in a newly set up tank with no bacteria (the Cycle product you mentioned in your other thread is useless), the ammonia will start rising immediately. After about a week there will be a small amount of bacteria to begin processing the ammonia which means there will be nitrite in the tank. In another week or so there will be a small amount of bacteria to start processing the nitrite so there will be nitrate in the tank.
Unless you have test kits so you know what those levels are, your fish will die from ammonia and nitrite posioning or they will catch white spot from the stress. During a cycle with fish, you usually have to do water changes every day to keep the ammonia and nitrite as close to zero as possible until there is enough bacteria to process it all. And even then, it is only cycled for the fish you have. Adding more fish means you have to go through the same thing again as the bacteria have to reproduce to increase their numbers enough to handle more waste.
By comparison, a test kit is extremely inexpensive. You can buy an Aquarium Pharmaceuticals Master Test kit for about $25. It will do well over 100 tests. I've had tanks for 2 and a half years and still haven't gone through all the solution in the first kit although I have had to buy an new ammonia and nitrite kit for about $5 each. But $35 in 2 and a half years is very cheap compared to what you spend on other things and it's a lot better than spending your money on more fish to replace the dead ones or ich treatment (talk about expensive).
Obviously, I'm an advocate of fishless cycling. It's more humane for the fish and a lot less work for you. But even if you do decide to cycle with fish, get the test kits. They are a must. Start slowly with only 3 or 4 fish and feed them lightly. The less food they get means less waste and less ammonia. They won't starve.
Hope this doesn't sound like a lecture. I just wanted to give you all the details of why you need the test kits and also how the cycling process works.
