Re: orange algae i would ask the store how long ago the rock came in. also if the rock is in the process of curing or already cured. you had said your lr smelled like a sewage plant that is the rock curing and having a lot of die off. fresh fully cured lr has no smell. if it is fully cured you should be able to put it in the tank with no problems. one fish store i go to has huge vats 1 for the curing process and another that the rock gets transferrd to when it is done and ready to go. we bought the fully cured stuff and added it to the tank with no problems but it was only out of the water about a half hour or so.