Ok. My parameters are fine. I very rarely have a death of anything in my tank. I have turbo snails too and they are fine.
I have a RSM 130 and the stock tubes which are two T5 s. They are on from 11 till 7pm. So around 8 hours every day.
This red algae started on one rock and them spread. It's not like the green hair algae that was everywhere, it's more like little patches, especially in nooks and crannies where there is less flow.
Not sure on phos readings but I use RODI
water at around 0ppm from my own house and use RSM coral pro salt mix.
Change 25 litres most weeks.