Hi Mike
this is the info from the chem spec web site
No more need to acid rinse this detergent will neutralise your alkaline pre sprays whilst it cleans.
pH @ use: 3-4 The above text would certainly give the impression that it would neutralise high PH pre sprays, with a " at use " ph of 3 - 4 .
I will have to do a PH test myself ?
Otherwise Chem Spec are giving misleading information ?
I hope that the 100 % wool, pure white carpet, that I cleaned with it today will not be all brown and patchy in the morning

Chris