I have a system set up on my FW and it does make a cool effect at night. It also made my fish more active during the day. I built my own and I used 9 plue LED's for a 48" tank. I made acrylic housings for them and they cover the entire tank. The key to putting moonlight in is you need to leave some dark spots so if your fish do not want the light then they can hide out. If you need any info on how to build a system let me know, I have built and sold numerous systems.