Glass thickness for 5’ rimless

[Stigigemla]

I have 1 1/4 inch and thats managable. But I never move the scraper vertically near the surface.

 

[mtraylor]

Probably about an inch

I measured mine and I have 1.5" at the top. Total volume aquarium is 255 gallon and it allows me to get my whole arms in aquarium to clean etc if have to without any water issues.

As far as cleaning the top of your aquarium, you can use a razor blade gingerly so you don't scratch glass to clean the top area. This will keep a wave of water from spilling over the edge. Salt on the outside is a pain to clean off once it dries. Also check your overflow area to see if its not constructed by debris. Oh, and I was thinking, you could reduce your return flow a little bit to bring down the water level a bit in aquarium and that may help you use your magnet.