The best thing I've had that cleared up the GHA are turbo snails. I had a small patch in a small tank...on a clam. I kept putting the snail on there and he'd eat a little and then leave. Put him on again and after a few times it caught on and cleaned it up completely and it hasn't come back. Someone also told me dwarf ceriths work well...and reefcleaners sells another small one that is suppose to eat it up.

I did notice if it was too long they wouldn't touch it so I had to "trim" it. I've never put chemicals in my tanks either. I didn't have GHA or any algae for that matter, until I put rocks from other reefers in my tank. I was worried it would get out of control, but luckily it hasn't.

Dee