Splashzone is some amazing stuff but I’m not sure it’s up to the task of holding up to water pressure over time. Is it possible it’s just a “void” or did you pressure test it??? Some of this nickel rod is amazing if the surrounding area is beefy and you can reach in and put a little “goonie” on it. But like a dear departed friend of mine told me. Don’t try to pretty it up to much after.