Test strips for coolant

[tsolson]

does anyone here use any kind of coolant additive? Are they worthwhile or just snake oil? I know my N14 has a coolant filter with conditioner, but don't see them on any other engines. The ag dealership i used to work at we saw the results of acidic coolant eating away the liners, esp on the old 903 V8 cummins in some of the four wheel drive tractors.