Pugman, ALWAYS clean top to bottom direction, NEVER side to side.
Those Kent Plastic orange scrapers, not the yellow metal ones, are what should be used. Softer acrylic pads, again, top to bottom and then the last 2-3", use the scraper with a plastic tip.
Credit cards are pretty good also, and better use for them.
A stack of 100 clean razors also is a good thing to have around, slow smooth top to bottom cleaning should never scratch glass, make sure the blade is always NEW, they are cheap, 180 ADA tanks are not. I use pure ADA AS for this reason also, does not scratch, power sand burps up and you can end up scratching things.
Snail shells also can come between the pad and the glass causing scratches.
Always apply the least amount of pressure, this will result in shallower scratches if they do occur. The pads= only for soft large area algae on glass and only the upper parts away from the soil. Plastic scrapers below that level and make sure not to get any sediment as you go down towards the line.
I scrape down all the way to the bottom. Then bend the scraper back to pull the sediment back away from the front of the glass. Then slowly lift it out. I do NOT scrape up and down in that area.
If you do these methods, you should have a nice tank for decades.