We are in the middle of having our gunnite pool resurfaced with quartzite. The contractor has patched all the cracks and removed and replaced most of the surface plaster and sprayed on grout (I guess) and then sprayed on a grey rough layer to which the new surface will adhere. We were delayed because we wanted to take the opportunity to replace our non-working 25 year old incandescent light and replace it with a new 12 volt colored light LPCUS11030. The niche from the old light is deep and the electric wire immovable so we had to drill another access hole and the electrician placed the wire in a conduit. The new light is much shallower and will require a plastic niche to which we will attach the new light. The electrician thinks he should seal the access conduit and the back of the deep niche with hydraulic concrete. 1) is it a good idea to put the wire in a conduit and how to seal and 2) how to close up the original deep niche? 3) what material/path would work best? Desperately need some advice here...thank you so much!!