I have had a Nero 5 on my 120 high for about a year. They did chintz out on the magnet for sure and it's a real pisser, considering the high price. From my experience, do not count on AI for support in this matter-I have a long email thread to prove it. The fact that it barely hangs on to 1/2" glass is shameful. It moves a ton of water, etc., etc., but if I had to do it again, I would give Reef Octopus a better look. Having said all that, it is dead quiet and really easy to clean. I pick up my "snail guard" from Melev's reef today.....this thing will inhale snails, starfish and anything that gets too close. Totally irresponsible on AI's part for the weak magnet and gaping holes at the back, w no guard from the get go.