On my first tank, I used HOB
filters. I tried a few over the years and some would cause deposits on the wall behind it. Others did not. I used to put a piece of clear plastic on the wall behind the tank. Never had issues after that. When I moved last, my tank had been in the same spot for 5 years. No problems there.
This was a 38 gal
though. No monster tank experience.
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,