Ok I have another question, for the 7 pounds in my tank there are 3 pieces I purchased one then had it in my 10 gallon with regular light for about a week 1/2. Then I bought the other 5 pounds (2 pieces) and put it all in the 50 gallon with the T5 lighting. Well the two I bought later are looking good but the first on eI bought is kind of whiteish. Is it dead? Do I need to scrub it? I am not sure whats going on. I will get a pic if you guys would like to see it.