No not at all, even though Chat GPT said the math equation, it’s not accurate for open pools under the sun, the metrics is out of that they says the boards at all of the internet. I read in depth that ORP at the end can’t have a link with ppm of free clorine direclty. But in generally ORP is better than ppm, because with this way you can see how much clear is the water (whitch is the hole point in the end) and ppm they say only the free chlorine (which is not sure if the water is clear but how much chlorine is in it).