I really dont know what effect moonlights would do to my livestock.....what I do know is, with moonlights it makes the tank pleasing to look at at night....You could buy a moonlight mod from Nanotuners.com but it'll cost you more...$25 maybe, alot more than $1.97......you could also buy a surface skimmer for I think $15-$30....but in my case, since I do like crafting things with my hands, I just made it myself...I think its on the DIY INDEX.....I used a Sega Game Cartridge and spent 99 cents. Though for those who arent really blessed with skills in DIY's, they'd probably be better off buying a ready made surface skimmer or any ready made mods. I would rather spend my money on the critical stuff....anyway, let me check where I posted the Surface skimmer I did....its very easy to do.