I am doing hard plumbing but got the silicone to run from pumps to dampen vibration .. also got the uv mount comingFunny thing is I ordered new lines and fittings from BRS last night and ran into the same thing. The bulkheads I ordered from salt water aquarium as they were nearly half. I’m switching to all soft plumbing. In all my years of aquarium keeping I’ve prob has zero leaks from my soft plumbing. And countless leaks from my hard plumbing.