If so get a cheap TDS meter and you’ll know the ppm fairly accurately
I’d probably need a good one to get any reliable results. I have a cheap one, but it’s fairly useless. It came with our under-the-sink reverse osmosis system, and it won’t give the same reading twice in 10 times from the same glass of water. But I’m not convinced that the ppm of the CS is all that critical. The proof is in the results.