12litre w.c cistern?

[anhbrown]

I'm plumbing and gas but looking for a while. WC cistern which I can fill with maximum water on my own building a extension with a very shallow fall on the drains about 1 in 100 so I'm looking for maximum water discharge to help flush through on every flush I know on some cisterns I can fit a fluid master with adjustable internal overflow to squeeze a bit more out of but looking for a big one it will feed a doc m pan so can be low or even high level for better flushing again! And yes I know regs 6 litre max but u gotta do what you gotta do its my own place any help folks

 

[JCplumb]

Urinal cisterns are larger than w.c. cisterns, might be worth looking at those.

 

[anhbrown]

Spot on jc Dudley do a 13.5litre urinal cistern looks just the job ..I love this site people always get back with ideas thanx again....

 

[ShaunCorbs]

Only prob it's plastic does this matter ?

 

[anhbrown]

Only prob it's plastic does this matter ?

Pot would be better do they do em?