My LP-100's run through 50mm manifolds a PVC male/female elbow is a perfect fit for the rubber adapters then using spa check valves with spring removed
(or else your adding a ton of extra vibration as spring forces the valve closed on every cycle gravity does the job just as good )
then the manifold runs underground by the time it exists to the fish room is dead quite 😄
lp-60's work with 15mm PVC pipes
always do airline manifolds in a loop so pressure in equal to all tanks
change the flapper valves at least with every second diaphragm change and clean out the very bottom filter down in the baffle and keep at least 0.01mpa / 1.5 psi / 1m h20 back pressure so the diaphragms are not over stretched
