This is more of just a handy trick not necessarily saving money. I've been fighting gha for a while in my 90gal. It really loves to grow on the back glass so I figured this out. I have some tubing that I use to siphon it all out and I first zip tie it to this algae scraper. Then get the siphon started and run the scraper up the back glass starting at the bottom. The tube sucks all the loose gha out and keeps it from getting everywhere. Then I just cut the zip ties off, put down the algae scraper, and continue cleaning the tank. You could also make the algae scraper out of a pvc pipe and slide a razor blade in the end.
Before:
After: