I have a really crappy pet store across the street from me... It used to be a good one but the new owner doesn't know anything about fish... He has some saltwater tanks that have been sitting for about 6 months and the has a clown or two in them... He has lots or rock in the tanks that has algae and other things growing on them. Would it be a bad idea to buy the LR off of him and if so, how should I treat it before putting it in my tank