I wasn't asking if you knew the difference between cyano and coralline, I was asking if you were sure that you were NOT getting cyano or coralline. I asked because your screen is very red looking, and contrary to the name "red turf algae" it is actually more brownish-red, not purple-red or blood-red.
What you are growing on your screen appears to be cyano algae or cyanobacteria - "red slime". You do not want this in your tank obviously, as it is extremely difficult to get rid of. It is the same stuff that was growing on the bottom of your tank that you mentioned.
I believe you are getting this growth because you are using the improper lights for your ATS. You are using 10,000k and Actinic 50/50 PC bulbs, which is the completely incorrect spectrum for green/red turf growth.
Cyano is ugly if it gets in your DT of course. An ATS screen growing GHA WILL eliminate cyano, eventually. Actually, if your tank is overrun with GHA and other nuisance algae, SantaMonica has stated that there is a possibility that cyano will appear after N and P drop to zero and all other algae disappears, but that the ATS will eventualy out-compete the cyano and it will go away. I have yet to hear someone complain about getting cyano after running an ATS though.
I don't think I've ever seen anyone intending to grow cyano on an ATS screen, your system appears to have good water parameters, however there is so little we can tell from the small fraction of parameters we test in the marine aquarium.
I think you mentioned that you intend to switch out the screen and lights eventually, but you might want to do that sooner, because I don't think you really want cyano growing on you ATS screen.