Hello, I a new to the whole reef tank hobby. I set up my tank 10 gallon tank with live sand, live rock, filter is 150gph. It has carbon and a filter and some bio rocks. The tank is at 75 degrees. Using two 25 W light bulbs. I'm not sure what the white stuff is growing on the rock. Is it something bad or is it normal? How do I get rid of it if it is bad? Any help would be appreciated.