What is this Reddish brown Algae/Bacteria?

[Emi2852]

Hey guys! I’m wondering if any of you can help me figure out what this algae is! And some potential solutions to get rid of it.
The snails don’t touch it at all.. but graze over top of it all the timE.

Thanks!

 

[Gulf of Persia]

Hey guys! I’m wondering if any of you can help me figure out what this algae is! And some potential solutions to get rid of it.
The snails don’t touch it at all.. but graze over top of it all the timE.

Thanks!

Check your alk. Something is imbalanced. They will disappear once you find out ur parameters

 

[Flippers4pups]

If it can be easily blown off, could be cyanobacteria.

 

[Greg P]

How old is your tank?
Tell us it's age and about how you started it with lots of details.

 

[Emi2852]

How old is your tank?
Tell us it's age and about how you started it with lots of details.

My tank is about 5 months old. I started with live rock & dry rock and let it cycle with dead shrimp then added 2 zoa frags. within the last two months the Zoas have began to Shrink away and don’t open anymore.. I’m still trying to figure that one out. After the Zoas, after about a month I got a Duncan frag with 3 heads, it’s growing 4 babies now as well as a torch frag with 3 heads and I believe one is starting to spilt. About a month ago I added a 2 Yuma mushrooms and the rock they were on had 2 babies which are slowly getting bigger. I don’t have any fish yet, but I feed the corals 3 times a week.
Pineapple sponges have popped up here and there as well as tuns of little feather duster tube worm things. They’re in a white casing and have red feathery things.
The mystery algae stuff is only on the very top rocks where the light is the brightest. My lights run for 12 hours.

Every time I’ve tested the water is shows undetectable nitrates and phosphates. I have a carbon bag in a filter & some filter floss. There is no sump or protein skimmer (I’m looking to get one in the upcoming year.)

My alk is usually around 10-12dkh
Salinity is 1.025
Temp is 26C
Iodine: 0.05
Magnesium: 1350Ish
Calcium: 420