glad to see theyre eating it up and its working but until you take care of the food source, the GHA will just come back. GHA growing mostly on the sand tells me youre not cleaning your sand well enough. what you could do is swap your sand bend. this was the steps I took when I had a gha outbreak in my 29.
- drained the water down low enough that most of the rock was exposed, but the fish had room to swim. probably left 3-4 inches of water in the bottom. now I was bare bottom so I didn't have to swap sand.
- sprayed 3% undiluted h2o2 on all the GHA, not just a mist either... I soaked it. waited 2 minutes and sprayed it again.
- scrubbed as much of the algae off as I could with a stiff bristle brush.
- sprayed yet again with h2o2. (at this point my tank had been drained about about 8 minutes and my coral had been exposed the whole time)
- refilled the tank with clean water and left the lights off to allow the tank to settle before being blasted with light again. figured it was stressed enough.
lights turned on the next day and I swear there was no algae left and it never came back.
