I pulled the original holding tank out, after I pumped it out. When doing the plumbing I used a T that had 1 1/2 barbed ends on each end and a crew in 3/4 barb and hooked the vent hose up to it so it would create a vent loop. Installed a Purasan system in its place and used the through hull that the macerator used. I installed the cycle button high in the bathroom so it wouldnt get wet. I also got power to the Purasan with the macerators existing wire and circuit breaker. I just had to bypass the macerator button.