reefadvice

Is this alagae is good for tank ? This red & purple type And can you tell me what is this thing which is eating my alagae Is it hermit crab ? should i take this thing out if tank ? Or is it eating my dead algae

Hello guys, i am new in Reef world , my tank is now 3 months Old , and i have this 3 different alagae in my tank Now it is 80 gallaon tank Now can any body guide me how to get rid of this alage ? Is there any Fish ? Or snails ? Or crab which can clear it or i have to do my self ? Or it will...