I have the same thing and trust me .... you could pack your tank full of snails and they wouldn't dent it, actually they only make little circular tracks in it and never really get it off.
I've checked my PO4
levels and mine are reading under 1, I only feed every other day and very light because I only have a clown and a Gramma. I feed frozen Mysis, Reef Mix and every now and then some Cyclo-peeze.
I've gotten so used to cleaning it everyday that it doesn't bother me anymore ... not as much as the dang MicroBubbles from my HOB
Do you run a skimmer? I've been told that if you get a skimmer it will clear your water and any thin film algea off the glass, but I don't know how true that is!
All I know is I'm watching for a good one (HOB
of course) to become available and I'm getting it.