how to remove dictyota

[dmh41532]

I had a very bad infestation of this algae, a few weeks ago, I bathed the rocks, corals, the pumps, sand everything in a hydrogen peroxide solution, which I thought removed all of the algae. Now, I am finding pieces coming back on the frags and rocks.....Nothing eats it, water parameters are nitrate 5, nitrite, ammonia and phosphate 0, this stuff won't die. is there anything else I can do.

 

[djkms]

Naso tangs eat it.

 

[dmh41532]

I only have a 20L, so a naso won't work, as much as I'd like to have one.