Mine is -12 but that only because I'm using the port on the GroupA pan, -10 is plenty as it allows for bends in the hose without it becoming too restritive.
Just remember it's a gravity drain so it MUST go downhill at all times.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.