GHA? Turf Algae? Something else?

BraxtonF · 2026-06-03T11:27:23-0400

Not too sure what this is, haven’t dealt with it before. I’m feeding every other day. Not a ton of food, running only blue lights. Whites were turned on to show the algae better.

Video of algae

Mr. Mojo Rising · 2026-06-03T11:36:49-0400

It looks like green hair algae to me. I notice not a single one of those algae hairs is moving, you might want to get more flow in there.

BraxtonF · 2026-06-03T11:44:07-0400

Mr. Mojo Rising said:
It looks like green hair algae to me. I notice not a single one of those algae hairs is moving, you might want to get more flow in there.

The flow was turned off completely for the video, this area has the most flow in the tank.

slingfox · 2026-06-03T12:00:58-0400

It looks like turf algae. I dealt with the something very similar when I started my first reef tank with 100% MarcoRock. It battled it for 6+ months and it eventually grew over almost the entirety of my rockscape despite having a very large CUC including urchins, dozens of snails (probably 50+), pithos crabs, emerald crabs. I scrubbed down the rocks at least a dozen times including 4+ times pulling out all the rocks and doing a deep clean outside the tank.

I hope you have better luck. The turf algae I had was super dark green may be be different. I ultimately did a tank reset where I replaced all my rock with 100% ocean live rock. No major issues with nuisance algae in the 9 months following reset.