I’m about to start going big on my tank with fish. When I first bought my tank I threw a pbt in there. (bad idea obviously but didn’t know at the time) that pbt got some ick or velvet, couldn’t tell and it died. So I wanna start quarantining my fish. I have a 40 gallon I think it is Home Depot box thingy, but no filtration at the moment. What is the most budget friendly filter I could get that still gets the job done? And last question, when I quarantine a fish how long should I quarantine it and how do I know if it’s ready?