[Nano]

Anyone know where I can get some super stupid ridiculous strong magnets around edmonton? I made up a diy 3d background but ive tried 3 of the strongest fish safe adhesives and it won't stay on the glass once the tanks full it wants to float free.. its frustrating so if anyone knows where I can get some of those rare earth magnets or other suitable ones let me know asap please this is the only thing holding me back from getting this damn tank running.