Chan, thanks for the feedback re the Tab 400 ground. I had to add to my first post to explain how I got to a fully effective solution. Also, I wanted to thank you for your 201 postings re Alde heater fluid and tools. I bought a refractometer and PH tester, following your suggestions. FYI, a new gallon container of "Century Transfer Fluid 19910-C6, which is what NuCamp uses tested on my just-calibrated PH instrument at 9.75, at 17.5 degrees centigrade. The fluid in my trailer, after one year, tested at 9.65. Interesting! I may let it go a tad below 9.5 in the trailer in my case, given my new gallon comparison. Nice to be able to keep track, and not change too soon!