New lite, new leak

[b.lowry]

Hi all, new guy here. Recently, last weekend, I replaced my pool light fixture. Since then the pool has been leaking. I went back into the niche and sealed the conduit hole, with putty, for a temporary fix to see if that was the reason for the leak. It wasn’t. I filled the pool to a marked level and over night, no motor running, the water level dropped about an inch. I don’t see how the water could drop so fast even if the putty wasn’t doing the trick. I also let the water drop lower than the skimmer intake to verify that the leak wasn’t from the skimmer.
All I did was replace the lighting fixture. I cut the cable from the old fixture, spliced the new fixture cable to it and pulled it through the conduit. Then i screwed the fixture in place. It wasn’t a perfect fit, but; it is a wet housing and the old fixture didn’t have a gasket and the bottom screw was missing so it wasn’t a ”perfect” fit either. Any ideas?
thanks in advance,

britt

[ChuckGeo]

There are numerous paces that can leak in light niches. You will need to "dye test" suspected areas to confirm the leak. First I'd double check the putty seal at the light conduit. After dye testing the conduit, place some dye at the joint where the conduit is welded or bolted to the back on the niche. If the niche is copper, it'll be dark reddish brown color if it is, inspect the interior of the niche for holes. Next we come to the face plate, you'll want to check for leaks between the back of the liner and the front of the light niche, there should be a gasket here. You mentioned that a screw is missing from the faceplate, if so, you could have a leak at the screw hole or between the back of the liner and the front of the light niche at the location of the missing screw.

Most cases of a leak starting after a new light is installed are either light conduit broken while pulling the wire or at the connection where the conduit attaches to the niche was weak and opened up when you pulled in the wire

Keep in mind that it might not be the niche at all. How much does it loose in 24 hours with the pump on?