As I've been reading profiles of fish I've come across a few that warn you they are jumpers. Mainly it states you should have a tight fitting lid. I can't imagine any of these small creature being strong enough to open a lid, especially if you're going to have a canopy. The glass itself should be heavy enough, but, if you're concerned, keep a small load of something on top, keeping in mind that it should not be too heavy risking the lid to break and sending glass debris into your tank. A small book should do. Try doing a
DIY latch for it if you are still concerned. Some glass adhesive and a sliding latch.
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