What is this stuff?

[StacieH]

I am relatively new to saltwater aquariums. I've had my tank (75g) up and running for 2 months now. Everything has been great; tank cycled like a charm, and I've got about 55 lbs of live rock.

So far I've got one damsel, 3 shrimp (1 blood shrimp, 2 cleaners), 4 astrela (sp?) snails, 14 narcissus snails, and 3 hermit crabs.

Lately, I've had a lot of this strange, hairy-blob looking stuff popping up on my sand. At first I thought it was waste from the narcissus snails. But I clean it up, and it comes back. Here is a picture:

Any idea of what it may be, and WHY it's popping up? The last time I checked the water the parameters were perfect:

pH: 8.0
ammonia: 0
Nitrite: 0
Nitrates: 20
temp: between 78-79 degrees
salinity was 1.025

 

[SubRosa]

cyanobacteria

 

[StacieH]

Thanks. Looks like a larger water change is in order to get the nitrates below 20. And I think I'll add another powerhead to the mix to catch that corner of the tank. It is mostly in one area.

 

[Sawt]

word to the wise..get rid of the damsel when you start to think about stocking fish..I had one..they really(in my case) are cheap for a reason..my domino caused havok,killed a purple fire fish,as soon as I took it out, the whole tank changed..the pecking order is much easier.