i looked on the boards and found many answers. i have these rocks i was thinking about putting in my tank. they were given to me from someone who had them in their house for many years. they been sitting in a bucket for a year or so. should i still boil them? i was thinking of testing if the ph lvl changes in the water. how long should i leave them in water? some have crystals on them. will they effect the water? anything i should know before putting them in?