Everyone that said clorox can be removed easily by putting the tank in the sun or rinsing it well is RIGHT! Clorox is easily deactivated by light and has a very short life of activity. I have used a lot of clorox in indoor tanks that couldn't be easily removed and have had no problems. It can be rough on certain materials though, especially rubber fittings. Clorox is the best, but vinegar is good too and very safe. When you get finished disinfesting the tank, fill it with water and get all the filters running (sans the filter media) and use a capful of Prime/50 gallons for a day or two. Whatever chlorine residue is left (and shouldn't be much) the Prime should deactivate or detoxify.