When you say filter return, I'm assuming you mean the suction line back to the pad correct? And you are saying that the electrical conduit for that light or the wires themselves are somehow incorporated into the suction line? Maybe we need to see a pic or two.
Also, how far you lower your water level depends on the type of pool and/or cover you may be using. Can you update your signature with all of your pool and equipment info? See mine as an example. Post a couple pics of your poll and decking as well. That will help in your replies.