You can't rely on a TDS pen to give the right reading. I bought a new one that reads in 1ppm increments as my old Hanna is a 10X which is fine for nutes but not near fine enough for CS. I run my CS until I get a 6 or 7ppm reading which
according to a couple sites you multiply by 2 or 2.5X to have a close approximation so I consider mine to be about 15ppm. Totally clear and like I said there is no sediment on the bottom of the jug from the gallon batch I made in May 2015. Almost out so time to dig out the gear and make some more. Wife feeds it to the chickens and uses it on their wounds and ours too.
I cut a Canadian silver dollar in half and attached each half at the end of a 6" silver wire and just submerge the lower portions of the coins in the distilled water. All the silver is .9999 pure and I buy gallon jugs of distilled water at the drug store making sure it's not the brand that has fluoride in it. Reads 0 or 1 with the TDS pen when I test it. I diluted 1000ppm test sol'n down to 20ppm and the pen reads 19 or 20 when I check it so I know everything is pretty darned accurate.
View attachment 4029258
I run the CS thru an unbleached coffee filter to get all the particles out. Saving all the used filters until I figure out some use for the bits in it. Bandages maybe?
View attachment 4029279