Few things that it can be from. New set up, over feeding, phosphate are up. Clean up crew can help. More water current, add some bacteria to help. If a new set up it will need to run its course.
ideally you need to find your source of food for the algae but considering you found the source and stopped it you can dip or spray with hydrogen peroxide. GL
It's not really high but enough to keep your nutrients high which will feed the algae. Might need to change filters or DI resin. Once you fix that you can do some water changes and even if you get phosphate lower you can still have that algae. I would try adding some bacteria. Just keep siphon it out.
OK. TDS above 0 is too high. Are you using RO/DI unit? If you're using RO only (with or without sediment and GAC fiiters), you need to add a DI filter. Check out Bulk Reef Supply site (and call, email, and IM them with questions) to add a DI unit.
If you already are using a DI unit, it may be time to change out the media.