PPM Testing for Soil

Good day!

I wanted to clarify my question I asked a few days ago on RIU: I was wondering if its even worth testing the PPM that's going IN (nutes + water) to the soil medium, and then testing the run-off of it? It doesn't seem like I would get an accurate reading in the end, because its soil hahaha. How is an inaccurate reading of run-off PPM supposed to help me determine how much nutes to put in next time?


Thanks in advance!

Yes this has been ask before and the argument goes on. Maybe later on today I have a little bit of sunshine mix 4 and I'll run some water through it to see if the water's ppm goes up this would be a fair test to see if it effects the ppm wouldn't you say? Its not like MG or FFOF they both would raise the ppm's of the water Sunshine Mix 4 shouldn't raise itIf it raises it you would be right and it wouldn't be accurate~Can't do it till later I just did my little experiment with Sunshine Mix 4 that supposed to have NO nutes in it! So I mixed a cup of SM4 with a cup of my fine tap water that's 150 ppm when mixed with the dirt the ppm went up to 580 ppm that means the SM4 dirt has 430 ppm of what? So I'm thinking any run off reading of any type of dirt medium wouldn't not be actuate. I only let it set for 2 minutes maybe the ppm might of gone higher if I had let it set longer? Sunshine Mix 4 is great for freshly sprouted seedlings~I think they look better than the one I did in Light Warrior!

^ I think you're supposed to test the run-off of the liquid from the soil..