I have a Mag Float, good magnet for my 46gal the magnet says it's good for 125gal tank, I also have the Hammer Head float which kicks ass, real strong magnet especially for 1/2" glass it does a fantastic job on my 110 gal tank, the Mag Float is good but not as good as the Hammer Head float, plus Hammer Head you can change the scrub pad for the inside the tank piece, and cotton pad for the outside piece, no more having to buy a whole new magnet once the pads wear out, cya.
I have a hammer and when the cleaning pad get pad I change them. Just go to the LFS and buy a piece of scrubbing pad and cut to fit. I use the soft on the outside. works well for me. I also leave my magnet in the tank most of the time, just put it in a lower corner.