Dealing with dust algae

[gregzz4]

Originally Posted by 604reefer

No PO4 test kit , NO3 20ppm before WC and 5ppm after by the looks of it? Always hard to tell with the API kit and my eyes...

Keep up with your current WC schedule and see if you can get your NO3 to near undetectable levels. I'd not worry about a quality test kit for now, but instead get a quality PO4 tester.
And ya, adding a Nitrogen source at this point is not recommended. I only brought it up as an option IF your levels started mimicking mine.