Not sure who you’re directing this at and it would be better if you started your own thread with your question - you’d probably get more answers than posting the question here, in someone else’s thread.
That said, I’ll try to address your question but I’m not entirely sure what, exactly, you’re asking. So, I’m going to address everything I can think of regarding ppm/ec pens and their use. I DO use PPM readings and I also use a generic (a.k.a. “cheap”) ppm/ec pen, like what you’re describing. But, if you have a cheap pH pen, I’d be nervous about using it; and I would double check the pH reading with an inexpensive drop kit. The kind of kit where you fill a small vial with the water, put in a few drops of solution and match the color of the result to a particular pH value. Reliable ppm/ec reading pens are very inexpensive to produce so I don’t think there’s much need to ‘invest’ in an expensive one. In my particular case, my PPM/EC pen has become extraordinarily valuable and important; but more on that later.
Assuming your stated results are correct (again, I’d recheck pH with some drops) your water ought to be great for growing. At least if you are growing in soil. I know almost nothing about hydro but I do know they use lower pH water so you’d have to lower your pH. Your question would be easier to answer if you included the type of growing you want to do or are doing: soil, coco, hydro, etc? The ppm reading may be higher than some people want for their style but it ought to be fine for soil growing. Or, you could filter it. I’m using an RO system from Hydro-Logic for my high ppm well water. My advice, start with soil and use your water as-is, if you’re just getting started.
PPM is also used by some people to determine the amount of “nutes” they are adding to their water and, in some cases, to see what is remaining behind in their soil. Most nutrient companies list dosages in terms of “teaspoons” or “tablespoons” or some fraction of them but some companies also list the ppm reading or max ppm reading, which is a far more precise measurement. I’m guessing it’s more critical for hydro and most people just use the Tsp and Tbsp method but if you’re into precision, you can use ppm. To use PPM, determine your base water PPM of TDS (Total Dissolved Solids) and add your nutrients. Then, recheck the PPM and subtract the amount of your base water reading from that number. This difference will tell you precisely how much of the nutrient you added to your water.
If you want to check how much nutrient is remaining in your soil, catch some of the runoff coming out of your pot as you pour your known-ppm nutrient solution into the pot - this is your runoff. Check PPM of the runoff and the difference will be the amount that remains in your soil. That’s the theory, anyway.
In my personal case, my ppm meter solved my plant issues. I was chasing symptoms all the time. One batch of soil would produce different deficiencies in different plants and I couldn’t get them corrected. It was making me and Plant Infirmary Guru, Waira crazy! Lol! Long story short.....my crappy well water comes out at 1025ppm and most of it is ‘unknowns’ and NOT calcium. That’s before I even added any nutrients! This has caused all sorts of nutrient lockout problems - where nutrients are present and available but something is preventing them from being absorbed by the plant. In my case, I HAD to get a RO filter and that’s solving all the nutrient issues I was having, by giving me quality water to start with. The point is, without that PPM/EC pen, I’d STILL be chasing nutrient deficiencies and just throwing more nutes at a problem the couldn’t fix!
Hope this helps. Probably way more than you wanted but I wasn’t sure what, exactly, you were asking. So I threw it all out there. Lol! Happy growing!
P.S. If you have further questions, start a new thread somewhere and tag me in it by typing the @ symbol just before my name. Like @-DTOM420 without the dash in there. It’ll let me know you want me to come look at it. But there are a lot better growers that will see a new thread and will give you better advice than I can!
