How to tell ACTUAL ppms? ( Explained inside)

Good evening again everyone. I had been battling some low PH issues in my soil. I added dolomite lime prilled and top dressed / worked it into my soil the other day.
I’m using jacks 321 and my runoff ppms have been 800-1100 solid everytime. I’m watering every 2 days to 20% yadda yadda.
The tricky part comes since I added the dolomite lime. Obviously this stuff doesn’t dissolve right away, and will add to my PPMs.
When I checked my runoff 2 days ago they were super high like 1500-1700 or so. Obviously the dolomite lime will be impacting this but I don’t know how I can calculate if my girls need to be watered just water or with nutes. I don’t want to risk burning them but I am pretty sure the spike is due to the dolomite lime and not the nutrients not being absorbed etc.
What would you guys do in this situation? I’m in flower and don’t want to starve my girls even for 2 days but if needed I will.

I normally judge by the way the plant reacts I don’t think trying to calculate the PPM going in and out is going to help you … If your looking to keep it with in a certain range that’s fine the plant will let you know if it’s happy if she needs attention … example I can have 5 different strains growing at one time and they might all eat different … so no black and white answers …


That being said I’m not an expert

Exactly what I see every grow. I just let minor issues ride and I always harvest a good batch.


1:1 soil slurry is only way to tell actual ppms and ph in root zone.

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I agree with @Docnraq. Adding lime can help soil in the long term but generally speaking its not a good fix for immediate results. Any decent bagged soil already has lime in it. It breaks down so slowly that I wonder if its in there simply to appease consumers.
So are your plants suffering somehow? What prompted you to try to fix the soil?
I’m not criticizing, Just curious.

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Have what I’m assuming is a CalMag issue due to not being able to absorb. It’s only in my pot with oceans farms which I’ve read more threads than I can count with PH balancing issues so I know I’m not alone. PH was in low 5s and I’m bringing it up. About to water and feed right now I’ll see what I’ve done if anything to bring PH up. Also if doing a slurry test wouldn’t that still count the Dolomite Lime? Seeing how it’s literal pieces of lime throughout my soil I don’t see how that will be any different? ( Like pouring sand into a water bottle and testing the water, the sand is there and will make an impact)


PH out is up to 5.9 now so yay it’s getting better.

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Hope it gets better.

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I understand what you have read. Now I need you to understand that just because there were alot of issues for others doesnt mean its your problem.

You been at this issue for a few days now. If you want your soil PH and PPMs to be on target, flush the soil till it comes back with an acceptable ph. Then feed at an acceptable ph and ppm.

I been using FF soil for for over a year now and im telling you, if you want to fix it. This is how. Flush with 3x’s the volume of your pot, with ph stable water, ph’d to 6.8.

Thanks and yea the lime is slowly making the PH better. I just need to survive until harvest lol

I did that, I flushed like 5 gallons through and it barely made a dent that’s why everyone suggested dolomite lime. Idk what happened with my batch of soil but when everything has been identical between 3 plants and the only variable that is different is the soil…as a science major I have to lean towards that being the issue lol

Your pot would have to be pretty small for 5 gallons of water to be 3x the volume of your pot.

You would be needing a dble blind study to prove your theory.

Mine looked worse than yours last grow and I ignored it. Harvest was fine. Got a pound dry.
I dont try to fix anything any longer. There is half a dozen things that cause that look on your leaves.

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So you are saying to do 9 gallons of water? I can try that but most people said 3-4x what I usually water which is 1 gallon?

That’s good to know. I mean it’s fattening up like crazy and has the most trichomes by a long shot compared to the other plants lol

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Oh and they are 3 gallon pots

Yes do that! 3 gallons in check runoff, 3 gallons in check runoff, three gallons in check runoff, do this untill the runoff numbers are in range. Ph between 6.5 and 6.8 with a low ppm around 3 or 400 is what I shoot for. Then after you get there 9 gallons, 15 gallons whatever it takes to get the numbers you want. Then do a feed, I go full strength but you can do it anywau you like.

Alright I’ll try that, I figured that would have been too much water but I guess doing it all once wouldnt make a big deal.

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This is what soil drainage is all about. Something I do, others maybe dont is to pour 1/3 of my flush water through, then wait ten mins or so for dripping to stop, then do another 1/3 of water and wait again, same after the final 1/3. Then I add feed. Takes a while but the waiting allows the soil to free up the salts and then drain allowing resaturation of the soil which will push out more junk.