Day 21 here and my 40 gallon AIO tank has cycled. Both ammonia and nitrite are now zero with Nitrate about 7. I have not had the lights on this tank as of yet and I have not added any live occupants to the tank. I would like to put in a piece of rock that has coralline algae or a frag plug that is small enough to get my tank seeded. Will it grow coralline algae with the light off? And when intro u Ching a small rock or frag plug is it ok to do a coral dip o make sure no unwanted critters are also included. Thanks