I've used for a few months, 20ml in 8l bucket. I put 20 ml white vinegar in too (recommended on another forum) as vinegar stops there being any film left on the glass and better cleaning power too. Trouble is although being very good, the vinegar degrades the squeegee rubber really quickly causing drag. I was turning the rubber at lunch time. I now just use the ecover and agree that it is the best I have used although not this amazing product as has been made out on various forums. Worth a try if you've not used it before.