I do that for my 300 gallon but dont really need them on my small tanks. Its still a matter of the curvature of the front glass. Dont know if adding the pad would compensate for that. The fluval one is designed for the weird curved tanks of theirs, want to try it... about $17 at KensThe pads we used went on the wet side of our magnets.
Yep the fun of sand. I have no bad scratches with medium to larger gravel tanks but sanded tanks all have something. At least with acrylic you can buff it out.I used a mag float on my 125 yesterday and somehow a smal grain of sand go into between the two magnets and I have a couple of lovely scratches in the acrylic now.... boo