What is this? Algae or bacteria?

[MatthewSS7]

This is in my aragonite live sand base. Showed this picture to guy at my LFS and he told me it was turf algae. It doesn’t look anything like turf to me. I’m pretty sure that it is a cyano or something. Hope someone can point me in the right direction.

 

[Flippers4pups]

Cyanobacteria.

 

[MatthewSS7]

Cyanobacteria.

I figured. I’m doing weekly water changes of 25% to try and bring down nutrients. Any advice on bringing it down? I know some people say to siphon it but I try to leave the sand bed alone. Tank is about 6 months old and I’m battling some GHA as well. Cleaned the GHA off all the LR last month and it just recently came back on the remaining previously unaffected LR. Probably going to take that out and brush and rinse with fresh salt water when doing water change.

PO4 is testing 0 but that’s with API test. I’m assuming it’s pretty low because it’s all tied up in the cyano and GHA.

NO3 is about 15. Test is also API it’s hard to tell exactly.

The cyano has been in the sand bed for months but was only green and never came to surface. It’s still below the surface. I’m thinking this is just part of the tank maturing. Maybe a losing battle? CUC seems to do okay at reducing GHA and is probably keeping sand surface free of cyano. Any advice is appreciated.

 

[Flippers4pups]

Probably consuming nutrients locked in the sand bed. It should balance out in time as the tank matures.