ok. Just curious. All my tanks have lids. Heat, jumpers and dust, etc. are my reasons. I noticed the tanks without lids are primarily planted, but a friend of mine had been running his brackish tanks without a lid for some time. Unfortunately, his Eel decided to see what life was like on the other side and now he has a lid on it. It was just one of those things though where some interaction with another fish in the tank ended up in unwanted results. I was wondering how many other monster tank owners run without a lid.