Anyway Paul the lab technician recommended using 19.5g ow DWB per 25l of finnished beer.
Here
And this is my water supply area
Being a curious person i entered my untreated water profile in Grahms water treatment calc, the treated (with DWB) water profile in line 5 and set it to 25l.
It came up with
Gypsum 12.18g
dihydrate 2.52g
Epsom 1.09g
Thats 15.79g of salts to get the same profile as 19.5g of DWB, so murphy add 3.7g of something else.
He also said CRS/AMS is'nt really necesarry at this level of alkalinity, I do still test alkalinity every time i brew and i may treat the water if it rises any more.
As for porters, milds and stouts, i carry on using my own salts to give the water a higher chloride ratio.
Anyway, my beers are tasting great at the moment and hopefully someone else in this area cam make use of this report.
Cheers Baz