Red algae excessively growing on sand...

[Oscar’s25Gal]

Hi guys - For the recent few months this red algae / bacteria has been excessively growing on my sand and every time i attempt to remove it with a gravel cleaner, it grows back within a week or so. Can anyone please help ID it and if it is my nitrates what is the most effective way of lowering them?
450 litre, 0 amm, 8.2pH, 0 nitrite, 25 nitrate.

Tank has been running for almost one year. Thanks.

 

[Dan_P]

Appears to be cyanobacteria,