Rust on Sand?

[Rickyrooz]

I'm not sure what is on my sand but it looks like rust. I've seen cyano and it doesn't look like that, I'm not 100% sure what diatoms look like but after doing multiple water changes over the past 2 months and even leaving the lights off for two days this stuff comes right back. I use the AquaC EV-120 protein skimmer and that stopped working for about a week and that's when this stuff started to take over the sand bed. I also have not noticed new coralline algae growth in awhile but the corals are still growing fast! Does anyone know what it might be?

Here is another picture with the flash on.

 

[mpoletti]

It looks like diatoms to me

 

[Rickyrooz]

How do I get rid of it? I performed three 30% water changes since it appeared and reduced the feeding to half.

 

[mpoletti]

I wish I had a definite cause or cure, but I have been battling them lately as well. From my research, I have found that the primary cause are silicates. Mine started after I mived a few things when I was aquascaping the tank.

 

[Zoalover34]

Just keep doing small water changes, they should go away rather quickly.. Do you have anything that sifts the sand, or any snails to help get rid of it?

 

[Rickyrooz]

I have a sand sifting star, I have some Cerith snails but not as many as I started with.

 

[salt newbie01]

I noticed an increase in the diatoms in my tank when my ro filters needed to be changed - made me think they were leaching silicates and phosphates back into the water.
With that said make sure your water change water is pure.

 

[roshi719]

Almost looks like a little bit of cyano starting. What source do you use for your water?

 

[Rickyrooz]

Ro/di

 

[eagleeyez5]

from the first picture I would have said that it was diatom.....but the darker spot in the the second picture makes me think that it could be cyano.

To help, what are your parameters? and how long has the tank been up and running?

 

[Pianoman]

Not rust for sure prob. cyano like eagleeeyesz5 said