Rust Colored Algea Growth

[Cessna22]

Hey all - I am new to reef keeping. My tank is approximately two months old today. About a week ago I began to notice a slight rust colored algae growth on my highest rock. One week later, this stuff has spread to almost every rock and also starting to accumulate on the glass and sand. I do not believe it is red slime as it takes some effort to brush off the rock. I am also very careful about not overfeeding. LFS said is could be coralline algae, but it seems too early for that. Please see the attached pictures to help me identify. Any help would be greatly appreciated!



Tank Info: 65 gallon, 62 lbs pre-cured live rock from LFS, 6 snails, 2 skunk cleaner shrimp, two clowns, one royal gramma. Salinity 1.025; Alkalinity 9; Ammonia 0; Nitrite 0; Nitrate <10; Calcium 300; Phosphates < 0.20; Temp 79.3

 

[rc1626]

Most likely diatoms. Very common in a new setup. Usually goes away on its own with regular tank maintenance. I've had them with every new tank I've set up. Good luck with the tank and happy reefing. This is a great site with loads of information and quite a few people with many years experience.

 

[thegrun]

+1, diatoms

 

[Cessna22]

Thanks - I didn't even consider diatoms because I thought they were only brown in color, but after looking at more pics online, I think you're right. Appreciate the comments.

 

[OrQidz]

I agree with diatoms. Mine always start on a rock like that too.