We called Martin Water to check and insure that our water conditioning system was operating as we needed. Don Sensenig was the technician that arrived. My wife and I found Don to be very knowledgeable and refreshingly polite. He looked at our concern which was a slight brown staining on the top part of a humidifier filter. He assured us after doing hardness, PH, and other tests (which we observed) that the system was working optimally. He explained why we were getting the residue and options we could exercise to address the issue.