I went to collect money for a job I did yesterday. I looked at the windows and noticed spotting. I thought possibly because it had rained this morning and that had caused it. I took a look all round the house and spotting was evident on nearly all downstairs windows. I felt that I had to go over them again as I couldn't leave them in that state. Maybe I didn't rinse enough? My TDS is 001PPM. Anyone else had issues?