Hi M/R I was in the market for buying magnifier coral viewer to view my corals from the front of my tank since I have no room to view from top of the tank due to plumbing and mesh cover. But I really can't afford the price right now and started looking for another cheaper way to do it. So I decided to go this route, I bought 2 large ferrite/ceramic magnets size I got is little larger since It was an experiment only. So size of my magnets are 8" OD and 5"ID they came as pair and I bought 5" diameter magnifier. Velcro stripes for the magnets. So I glued the magnifier on the once of the Magnets and then added Velcro soft side on the outer magnet that is going to stay on the outside and rough Velcro on the other side of the magnet where I have mounted the magnifier and then put them in the tank and I have perfect magnifier. They clean the glass and I can view my fishes and corals at the same time. I agree its extra large due to large magnets but in near future I will sell this one and make my self the smaller version. List of parts that I bought with cost are below.
exactly I have provided link for marinedepot selling one for 70 bucks and this is ceramic magnet I am not sure what is the harm in the form this being in saltwater but if its an issue I can paint this and seal it with either black or clear coat. but this works great I love this. I am going to order more magnets smaller sizes to make my frag racks and other stuff to hang in the tank.