Ppm comparison: feeding vs runoff

I know this has been discussed at great length but I didn’t see my actual situation. I’ve been using General Hydroponics full array of nutrients. Everyone looks very happy. I checked my tap water and got a reading of 67 ppm. Nutrient solution going in was 976 ppm. Runoff ppm was 276 ppm.

Ph going in was 6.24 and runoff was 6.01

I’m in my 7th week of flower and I know it’s late in the game, but I just wanted to get someone with more experience than I’ve got to chime in.

Like I said, the plants look very happy and healthy and are doing their thing. I’m just curious if my readings indicate that I’m doing something wrong or if I should have fed more

Nah. Im pretty sure (from the numbers) your not getting alot of runoff. A big thing you learn as you keep growing, is to pour slowly, in circles. Your dont want runoff immediately. Just enough to dampen the soil as completely n wholely as possible… then you add more. And more. Try to saturate the entire pot evenly…

Also when collecting runoff, try to get the later part. Not first few drops.


Thanks for the reply. That’s what I tried to do with collecting the runoff. As far as watering, I do it very slowly and go from plant to plant and then back to the first in order to let it all absorb before I add more.

Am I feeding enough based on the ppm going in? I see numbers of 1200-1500 but I’m considerably less than that at 976


Seeing numbers in around 1200 and out around 976 is fine. Maybe they can eat more.

Going in at 976 and out at 276 isnt.

Which is happening?

Going in 976 coming out 1276 is about perfect tho


I’m thinking my meter was wonky. A very similar number going in this time at 956 Ppm and now the runoff was 1017. Is that better?

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Muchos muchos.


Should I use nutrients again next watering or just water?

Just water again if you dont mind. You’ll be feeding again shortly

I think this is the first time iv heard that numbers out should be higher that in, always thought it was the other way around. Good to know

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In a perfect world you want 1000 in and 1000 out. 300 ppm over or under what you put in isn’t anything to worry about.


Good to know, thanks.

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