Cut a hole in plastic tank.

[crockett]

If you think this post is trivial, Laguna, read through some of the other ones on this site, you will cry with rage at the inane babble that some people pass off as "advise". Quite funny really

 

[PlanetThanet]

Hi... From BS 4213:2004 Cisterns for Domestic Use- Cold Water Storage and combined feed and expansion (thermoplastic) Cisterns up to 500 L - Specification 'Circular holes for fixing pipes shall have a clean edge, free from notches,and shall be punched with a hollow punch, cut with a hole saw, or drilled with a sharp cutter. Scratching or scoring of the cistern shall not be used for setting out holes' The Standard also details other requirements but I'm starting to nod off from the excitement of it all

Thanet

 

[Softus]

Do what suits you best and what works for you .

Is that your advice for the OP, who asked "what's the best way?"

 

[lagunaglen]

Is that your advice for the OP, who asked "what's the best way?" [/quote]
Cos you lot have given clear and consistent advice on the matter i guess