Is your tank covered?

My mbunas have jumped out before. Fortunately other than one time it happened when I was in the living room so I managed to put them back without casualties. Eventually, I put a more tight lid. I used to have glass top under the lights but it used to leave a small gap around the tank which was big enough for some species to jump out.
 
I've heard the hard splashes but never them hitting the top of the tank. However, I don't want to go against the conventional wisdom, and great depth of knowledge, by all who have responded. Covered it shall remain and I will work new lights around this setup. Depending on my light setup that I select, I will DIY something, unless I can retrofit my current setup from AH Supply. Thanks all.
 
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