1/3 cup of STPP?
I got my first order of STTP yesterday. I am using it in a TL and according to our water district's website, the hardness of our water is 300 parts per million (ppm) or 17.5 grains per gallon, categorized as "very hard."
Following the advice I found in a previous STTP thread, I added 1 TBSP at a time, agitated and then felt the water. The water did not being to feel slippery until I added 5 TBSP!
Can that be right?!?