You could probably use the edge of a credit card to do it. I know you're a young guy so probably don't have this problem yet but get one of the one's your mom or dad got unsolicited.
I wouldn't use a wire brush though
HI I hgave the pro scapper and it just does not seem to work for me!!! I also have the magfloat but it scathes the arculic and yes ther is no sand. which side of the mag floate which is made for arcyulic goes in the taNK. The hard side or the cloth side??
I have the acrylic mag float magnets, the hard side goes in the tank, but the algea free magnets work better email me and ill give you the site plum70rt@aol.com
For the longest time I used a credit card to scrape coraline off the front glass(heck...Visa built it so Visa can clean it)
A few months ago I bought a Mag Float...it does great. Just be sure to keep the cleaning pad clean...mine has done so well the Visa is retired.