best is to use thin piping- try to suck out the algae...I attached a air-hose to thin bamboo stick with rubber bands...to slowly suck out,,,,,,whille have another bamboo with bend toothbrush to scape exposed rocks...tedious but what to do- for sands...2 golden head gobies, 2 sand shifting stars..., 2 short hair urchins (from Ah Beng's)..+ with regular water changes,,,worked well for me!.also dont over feed!