I have a 10 gallon brackish set-up with about 5 gallons of water in it. I have one red claw crab living in there and it needs access to air, hence the lower-level water.
I'm getting a nice green growth on my rocks. What are my best options of getting rid of it before it becomes a nuisance? Trouble is, I've got the crab in there which means if I drop shrimp or snails, they're going to be lunch. What else can I try? I've been told not many due to the fact the tank only has 5 gallons of water in it.
There's got to be a way to get rid of all that algae. I thought about brushing the rock or running hot water on it to kill off the algae, but that will also effectively kill off the good bacteria on it

Advice?