4 inch filter sock hole size

[coffeetwitch]

re working my sump to add mechanical filtration. need to know what size to drill the holes for a 4" filter sock.

also need to know how much above the water line the sock needs to be.

pictures would also help.

thanks

 

[coffeetwitch]

I've found other forums with replies to similar question.

3 5/8 to fit the sock. 3 3/4 to have the ring sit flush on the mount.

Feel free to confirm or correct.

 

[coffeetwitch]

i bought a 3 3/4 hole saw. ring sits flush and no risk of slipping through. very happy with the fit.

side note.

i also made a diy 7" filter sock holder. i purchased a 7 inch filter sock. 6 5/8 would snugly hold the plastic ring. 6 3/4 is a looser fit and still will not allow the sock to fall through the hole and provide enough support.

i hope that this helps anyone else looking for what hole size for a 4" filter sock and what hole size for a 7" filter sock.