Tip for those of you that are looking for rare earth magnets: Daiso shops in the UAE are selling noticeboard magnetic pins. The magnets are 0.15" x 0.1" discs and hella strong! Suitable for all your tank needs!
They are sold in packs of 10 for 7 AED.
Here is what they did to my metal models on a metal tray:
And you can shake all you want, it won't budge :)
edit: forgot to mention you'll need a hammer to remove the magnet from the actual pin they come in :P
