Help and Advice

For about four months now I have battled hair algae. Last week i scrubbed it all from the rock and although its not coming back loads it is still growing back.

I change 20% of water weekly with home made RO/DI water
Use phospahte remover
have low nitrate - 5ppm
and I do not over feed

My clean up crew is only small (3 snails, 3 hermits) so im going to add to that but im not sure what else I can do now to help. I did have an issue with salinity. I was using a swing arm hydrometer which was...