Question about PPM

I am trying to figure out the whole ppm thing and how it correlates to nutrients and minerals. I am sure I am overthinking the whole thing. I have been doing some readings but not sure what the numbers really mean. Is it as simple as higher the number the more stuff in the water and run off water. The numbers are kind of all over the place.

Yeah for the most part you got it bro
And you can use those numbers when trying to figure out when to feed or how much to feed
There are range charts that tell you how many ppm you want for stage of growth
I’d have to search for since I don’t have them at hand but know the info is out there bro


Thanks I figured as much that I was over thinking it a bit. I have to do some searching for some charts. Thanks buddy

Any time bro
I use fox farm nutes and their feeding schedule has recommended ppm for each week
I have been trying to stay close to their numbers seems to be working out fine for me

I use the same stuff and my numbers are close to the ranges if not in them. It is the run off that is out of range but does that matter? I would guess fox farm refers to the ppm as a mixed water solution? and not run off?

1 Like

I adjust my run off to the schedule figured if my run of is in range or close my soil will be also
So if I’m high I’ll water a little more and lower it down while watching my ph at the same time try to get my ppm and ph in safe zone 6.3-6.5 ph and ppm as per schedule and I’m usually on lower side of schedule for ppm
But I won’t feed at all if my ppm reading say I don’t need to


Jumping in half asleep still… Sorry if I’m missing something…

If your runoff TDS is higher than what you are putting in, you are getting build up in the soil and should cut back on nutrients and/or flush (if it is really high). The plant isn’t consuming what you’re giving it.

Basically what @Countryboyjvd1971 said. Stop adding if your runoff PPM is high.

1 Like

I think you may have worded it better
Sometimes I confuse myself lol

1 Like

:slight_smile: No man. I started typing before I fully read. You had already said it.

Also, I stopped worrying about runoff. I just put the right amount in, at the right PH. Unless I see a problem, I stopped checking runoff. Just me.

I will use it to flush, to be sure I flushed everything out. Not there yet, though.


Thanks guys it is all starting to make sense now.

Not every plant is the same and some strains are very fussy some product chart ppm are just based on the mixed product in RO water but the charts can be a good indicator of when to feed if you are testing run off ppm on straight water cycle not feed cycle since feed cycle is a already adjusted ppm. For instance if running a water cycle on a 2 month old plant and my ppm reads under 600-700 I would likely feed next cycle if it read 900+ I would water again next cycle. The ppm is telling me that there is still nutrients available in the soil and that feeding again would only continue to raise it and contribute to potential lock outs.
Most feed chart ppm ranges are based on hydro use since unlike soil the ppm is easily controlled keep in mind a heavy feeding plant will have different readings then its siblings and less is more is always good policy