So last year I learned a hard lesson. Always quarantine new fish and have a hospital tank. Unfortunately I didn't do that and lost many fish as a result of disease some new arrivals brought. So I plan to set up a 10g quarantine/hospital tank. My question is when it is serving as a hospital tank but not in use, does it still have to be on (the heater and filter) running all the time? Can you just have water in it and if a fish needs quarantined then turn it on? Does turning it off kill the cycle?