Mate don't hold me to this as I myself have not used it yet and don't intend to for the time being, but I've read quite a lot about it and from what I can gather you mix it generally with a mix of 3:1 ie 3 litres of water to 1 litre of hypo. From research most people seem to go over the area with a flat service cleaner then if needed pour the hypo over the desired area and leave for 20 minutes then rinse off. Don't allow it to dry. I hope I have informed right and if I have not someone please correct me as I've never used it it's just what I have read on here.