Algae on glass reappears after 15 minutes of scrubbing!

sorry wrong thread in my original post....yours sounds like film algae which is microalgae. it is in the water column so when you remove the stuff attached to the glass it leaves room for more stuff to attach.

 

I checked the trites and trates and they came back at zero, the phosphates came back a .05. I use only RO/DI water for top off and water changes.
I recently purchased a Phosban reactor to help combat the issue, I have noticed the algae doesnt seem to form on the glass as fast now since hooking it up. I still need to get the Cyano under control and it has started to show up on the substrate more.