We have a high level toilet cistern in the outside toilet that needs to be plumbed in so i was thinking of buying the copper pipe and pvc pipe and having a go myself but as i don't know much about plumbing i was wondering if someone could help me as i'm stuck at the first hurdle. The stop tap don't have a nut but it takes a 15mm pipe so i bought a 15mm x 1/2 inch tap connector and it won't fit as it's to small for the stop tap, so i was given a 15mm x 3/4 inch tap connector but the part that should fit inside the stop tap is to big so i was wondering what fitting do i need.