I bought a 20g tank last week and was wondering if it would be safe to put the filter I would use in it into my 10g for a week and then put into to the 20g to jump start the cycle. Another concern I have is that 1 molly in my 10g had popeye 2 weeks ago, I treated it and everything is fine now but could I introduce popeye into my 20g by switching filters?