Black Looking Long Hairs Growning On My Sand Bed?

[bassdrummer1]

Yes about a month ago I started putting live rock and corals in my tank. Now when I look at my sand bed I see almost like a mold of black long stringy hairs growning? is this good or bad?

 

[-Nemo-]

Do you have a picture?

 

[ben1987]

my guess would be cyanobacteria. This is caused by low flow aeas, high phosphates, poor RO water/ not even using RO, feeding frozen foods without de frosting and rinsing it first.

 

[bassdrummer1]

nope use lots of R/O water. 0 Phospates. Maybe not enough flow???