NEW algae!!!

[Saltwater T]

OK now that i have almost completely eradicated a brown diatom algae and a green encrusting algae i now have some kind of brown/black algae covering my sand!!! any ideas what it is and how to get rid of it

 

[lando]

All algae presents for a reason. The usual drill...check for PO4 and NO3 in your tank and source water. Evaluate your feeding and lighting schedules. Go from there. Getting rid of algae is troublesome but with regular water changes (with good quality RO/DI water) and cutting back on feeding and lighting you can win.