I have a freshwater 75g acrylic hex which is 30" tall. Just set it up, w/CO2, Eheim canister and 30w of florescent lighting in the hood that it came with. Any suggestions to improve the lighting system? I cant hang a pendant from the ceiling. I do not have a hood. Their is a 17 x 7" opening on the top. Should I use something with legs? If so, should I get a piece of acrylic to cover up the opening?