The only thing you need to do is test your nitrates and phos. If you keep them in check you should see the glass stay cleaner for longer. Feeding less and using your lights less are band aids to the real problem (altho both can be overdone). A UV will keep the water clear but do nothing for the glass. I have a 240 gallon tank with 50 fish in it feed twice a day usually and run 2x400w MH lights with no live plants from 5pm to midnight and I can go weeks with out scraping the glass. Since I have setup the tank I probably scraped it 10 times. My phos and Nitrates are low. I run phos sponge stuff and do water changes...when I see a little funk starting to grow I know its time to change the stuff.