I have a 300g tank that was overrun by majanos. I essentially have shut the tank down other than keeping it heated and circulating. I have blacked it out from any light hoping to eradicate the nuisance algae and majanos. Will this work or must I take more drastic measures? The tank is over 6 years old so I hate to kill the liverock and start over from scratch. There are no fish or corals in it.