My new tank has been set up for a little over two months now. Lately I have an outbreak of brown algae all over my rocks and substrate. What can I do to clean up my tank a little and get some purple algae growing on my live rock? I bought some cleaner snails and crabs, is there anything else I can do. Also my pH is low how can I get it back up to 8.2? Please help I just want my tank to look great but I guess it is just a waiting game.