I'm going to set my 240l up at the weekend and won't be putting any fish in until a full cycle is complete however I'm wondering if anyone has done anything specific to help keep their cats out of the tank. It's got the lid obviously but one of ours (Yoda) is a devious little sod and at times I swear he is like the main Raptor in Jurassic Park. He sits there calm and calculating working things out!
I've thought of putting some sticky backed Velcro on the lid panels and on the black surround at the top of the frame with the other half of the Velcro attached over it when I don't need access. I figured that Velcro would be easy to remove without being a hassle but would definitely stop him or the other two from possibly getting a claw under the lip and wiggling in.
I found that I could keep my cat off things by putting pieces of scotch tape (sticky side up) on things I didn't want him to walk on. As soon as they step on it, they start freaking out.