Yeah you do, when they coil up they can take off like a rocket. And it doesn't have to be because they're unhappy, they might just see an insect on the lid and they can't resist going for it.
This lid is a recent replacement for a lighter one that was made from aluminum (which I replaced due to fears of possible aluminum oxide leaching into tank). I have a thread in the DIY sub-forum about it. This one is also partially filled with small pebbles and is tied down, so I don't think any Aro is getting out of there unless it's Houdini reincarnated lol.
