Hey everyone. This is my first time making a post on this site. I am fairly new with aquariums. I set up a 72 bow front tank for my parents and made a beautiful cichlid tank for them to enjoy. I recently have taken up interest in starting my first 20 gallon tall live plant aquarium. I started with a small tank because I don't have a lot of money for a bigger one. I realize smaller tanks are harder to start on. But my question is that I just ordered a HO lighting system, Coralife Aqualight High Output T5 Aquarium Lighting Fixture, 2X24W, 24 inch, and I was wondering if I added a glass cover to the tank, would it affect the amount of light reaching the bottom. I really want a cover because I am going to have cichlid babies in my tank from my parents tank, and I heard cichlids tend to jump out of the tanks a lot. Thanks for any advice.