Yes, you definitely need a protein skimmer, they gather all your fish waste, toxic ammonia symptoms, I have a 55 gal fish only live sand, live rock, also I would suggest a 8 watt sterilizer, especially if you have ich-prone tangs, this will kill 98% of the parasites, and keep your water crystal clear. As far as protein skimmer the bio-skim 600 is a good one, it acts as sub-filter too. that fish place 129.99, pet stores 200.00