Brown spots on anubias ID?

[NadiaG]

I have noticed there are 2 brown spots on anubias leaf. They just appeared today. Looks more surface algae like thing rather than in the leaf itself.

It's a 10g tank and I run 15w full spec fluorescent and 15w incan for 6 and a half hours a day, after that I run an LED blue light for another 6 hours.

Please help to ID this growth on the plant, what it is and how to treat it. All input is highly appreciated!

 

[severum mama]

Looks like diatoms- very common in newer tanks and most often goes away on its own.