RO bEfore and after

[hillegom]

The water in Vancouver has a low tds, somewhere around 10-15, if I remember correctly. There is a thread around where people wrote in their local tds.
I would do the normal water changes and cut down on the feeding for a while.
Try some cheato in the sump, with a light. It will take some nutrients out of the water while it is growing. Then throw it out or give it away. Its all about nutrient export.
As asked, what kind of algae is it? There are some livestock that will eat algae, depending on what kind you have.