We rehomed a cat from Battersea 2 weeks ago and are having problems keeping him away from the fish tank. We have resorted to sealing the lid with parcel tape and covering the top with tin foil, but I have just caught him with his paw in the tank again.. !!
The lid is a plastic sheet that normally sits across the tank. Our rooms are mainly open plan so there is nowhere we can put the tank out of the cat's reach.