There are several folks using them on 3/4" glass on here (ianiwane and SunnyX to name two). I ran them on my 3/4" tank for a week or so. While they did work without losing contact, the slightest bump would cause them to separate. As long as they are in a place where they won't be run into, you should be fine. I needed more flow, however, so upgraded to the MP60's. You can definitely run them on 3/4" glass though!