Possible diatoms or cyano

[damo7878]

Been having few problems with algae lately in my 10gal been running good 6months range of sps and lps all doing fine good pe and colours although growth is little slow tbh only 2 small clownfish and shrimp below is photo of the algae and current test results nitrate is very low just not on there and yes I no calcium is little high lol running rowaphos and carbon monthly changed no skimmer weekly water changes just can’t seem to make it go away any help would be awesome opinions etc

 

[DLHDesign]

First; welcome to R2R!

I'm leaning towards diatoms. Diatoms develop in new tanks as part of the natural cycle process, but if your tank has been up for 6 months, it's unlikely that it's still going through it's initial cycle - do you know that you got through it the first time?
From the pictures, it looks like it is mostly located in low-flow areas of the tank; is that accurate? If so, increasing the flow into those areas would help to reduce - and perhaps eliminate - the problem.
Diatoms also appear when silicates become elevated. Silicates often enter the tank from water that is not properly treated - do you use RO/DI water?

Lovely looking little tank there - lots of impressive coral growing!