I was pretty close to the same with my bottle. 1ml/gal = 1.80Another update with a different batch #0467FID101 - 1ml > 1 gallon > 1.89ppm
Honestly I'm ok with still using Coppersafe, I just know that I need to test each bottle before using. In my opinion, there are many products in this hobby that need tested each time you use them, salt being one of the big ones.
For those that don't see this thread, the 5ml/4gal directions will be quite a bit high...