brownish algie, long hair

[hallawell]

my tank is about 3 months old now, 300 ltrs, and is suffering quite bad from brown algie type hair on the live rock, and brown type ash on tank glass,my tank is running at temp of 24.3, ph at 8.16, and nh3@ 0.001.
i have turf scrubber running into sump, and filtration system that cleans water , begining to get a little bit frustrated as it seems to be getting worse,

 

[SPR1968]

We maybe need a full tank shot and also your nitrate/phosphate levels to help ID the problem

Its probably being caused by high phosphate if it has brown on the glass and might look generally a bit dirty