Black algae

[Josue787]

I am new in the hobbie i set up a 10gal tank 4 months ago. 1 week ago i notice some kind of black stuff is growing over my rocks. Any recommendation about what should i do to get rid of this ugly stuff ? I am using ATM salt thinking of change it to red sea coral pro. I do weekly water change. Corals are growing fast and look healthy.

 

[Copingwithpods]

Can't really make out its structure. Can you describe it a bit? Does it blow off the rocks, sway with the current, hard/easy to remove, create filaments?

 

[Josue787]

I could tell you that it is like a fluffy carpet with extremely short hairs. If I use a toothbrush to remove it small particles come out. After 3 days it begins to come out again and spreads throughout the tank. First picture is in my tank the other i found in google and is pretty similar(rock with coraline).

 

[waleedreef]

I had this issue before i dosed h2o2 and never comeback. try maintain phosphate 0.1 and less and nitrate less than 10 ppm. raise alkalinity to raise PH up to 8.4 prevent phosphate come to water.

 

[Sisterlimonpot]

I would venture to guess that it's some sort of sponge.