mrbee2828
Aquarium Advice FINatic
I'm not sure of the exact outer dimensions but it's 55mm plumbing on the 150. Basically, it's snug as hell with a 1.5" rubber coupling. If you go PVC on this you need a 2" T to go over it and a decent amount of tape.
As for the cap, yeah you need it. It acts like a muffler just like on the overflows. Without it you get the toilet sound which is almost worse that the splashing
As for the cap, yeah you need it. It acts like a muffler just like on the overflows. Without it you get the toilet sound which is almost worse that the splashing