I have heard that mollies are really good at algae control and I have seen that tangs are great at algae. I have 2 mollies in a freshwater tank right now and I'm just waiting for my tank to be fallow for 90 days because of marine velvet. My mollies have VERY similar behavior to tangs so I was just curious about mollies compared to tangs. Also I know tangs are a lot bigger so they probably eat more but I'm just curious.