Not sure if this will work for your tank, But I have Tunze Care Magnets in all my tanks and I am impressed by the quality design. They can be left in the tank, and you would have to work really hard to scratch a tank with one. They also do a great job on the glass which is another plus
I know J%L sells them. Not sure if anyone in Calgary sells them.
http://reefbuilders.com/2014/06/05/t...le-brilliance/