SOIL PH STUCK IN THE 4'S, powdered hydrated lime, pulverized dolomite, bottles of ph up, nothing is helping

so im going to try to be as detailed as possible because i (first time grower) am completely baffled, so i started my first grow, have a 5x5 with a 600w qb, growing (phenofinders) wedding cake and peyote critical in straight fox farms ocean forest. veg went pretty good besides my soil being loaded with fungus gnats (dont believe i over watered, think the soil came loaded with em). so i went from solo cup to 5 gal pot. plants werent large so i wasnt watering until i got runoff, because i didnt want to over water. watered every 3 or 4 days. when they did get big enough i didnt pay attention to runoff at first because i read a few places it didnt matter that much in soil, had very mild leaf problems but chalked it up to the undefeatable gnats i had. (big mistake #1) after a little while i noticed cal mag def. im using tap water but w.e, bought a bottle of calimagic cal mag, used that a few waterings and things were getting worse. so then i started measuring ph runoff, i was in the mid 4s to mid 5s. so it was really a ph problem causing these plants to lockout. okay so i bought some dolomite pellets, think i top dressed like 1 cup of pellets per plant (i have 6 plants), no change, then i read the pellets take a long time to work, so i bought pulverized dolomite, gave them all like a quarter of a cup and switched to flower (big mistake #2) because i couldnt let the plants get any bigger. still, no change in ph. i tried flushing the plants, that lowered my ph a little from 5s to the 4s. then a half a cup each of the pulverized dolomite, you guessed it, still no chamge. sh#t just wasnt working, read about hydrated lime and its a little dangerous to use, well im desperate so i get some and give each plant 1/4 of a cup. no change, some 1 tells me it could be a yeast problem, hit all the plants with a 1 to 4 ratio of h202 to water, thinking it should kill whatever is messing my soil up and the stupid fungus gnats. so now im scared im going to kill all these plants if i keep liming them to death so i focus on trying to fix just one plants ph by doing some drastic measures today. i gave it 1 cup of hydrated lime, did nothing to the ph... then poured half a general hydroponics ph up into a gallon of water, rewatered it, no change in ph. i cant get this ph up to save my life. now this plant has a fat layer of lime on top of it and i just dont know what to do from here. please someone help me fix this

my tap water is 60ppm (forgot to say that with the other plants today i ph'd my water up to 10 then down to 6.8 when i watered because of low ppm, that didn't do squat to them)

using a calibrated blue lab ph meter and ppm meter, (and a cheap ph pen just to be sure)

i recently started an 8x4 tent today too, mixed a cup of pulverized dolomite in with the soil hoping i wont run into this problem with that tent too
 
the use of lime i dont do,reguardless of how much you use the outcome is still a neutral 7.0,cannibis is more on the acidic side,so answer this,have you thought of doing a slurry test of your soil?
to late too anyway the lime jacked you for that,all i can say is damage done expect a hell of a ride,all the flushing you done has washed any microbes out and nutrients,the lime will stay ,but for your own concern do a slurry of the soil and see what you have
 
alright, thanks for enlightening me on the slurry test, doing that soon as the lights come on
keep in mind with all the lime in there your gonna have to feed less or you will lock the plant up,there are soil acifiers to drop the ph but i feel it to late for that,lime and acidfer just fight each other leading to no harvest,im give you a important tip though,next time when you use soil,reguardless of many that say check your runoff,disreguard,soil is a filter,our drinking water is the same filtered water,you cant get a acurite reading threw the runoff,just my opinion,to test after you harvest and flush that soil your using,keep note on how much water you use and what the ph is , do you know how to do a slurry test on your soil?
 
take this for example,you have a pit,you put in sand rock and charcoal,you fill that pit and filtered water comes out,were do the minerals go.
that said when you flush soil and it becomes mud,how long does it take for the mud to get ride of all the water and then how long to break it up for use again,might have been able to help you before all the lime and stuff,dont threat asking for help friend,im 59 and still ask for help,i use woodash for this purpose,the wood ash will leach out of soil quicker than lime and also you can add a little at a time to get what ph your looking for
 
I use wood ashes to raise my Ph if necessary, since they will provide nutrients as well as raising the Ph somewhat. Lime takes a long time to work it's magic and top dressing won't really help matters deep in the soil. When the lime DOES start working, the Ph swings are going to be problematic. FFOF is fairly full of nutrients, but not to the point that that it will drag your Ph into the 4s. Is there a chance that your Ph pen/device could be reading incorrectly? Your plants look pretty healthy for having a Ph so low, in my opinion.
 
keep in mind with all the lime in there your gonna have to feed less or you will lock the plant up,there are soil acifiers to drop the ph but i feel it to late for that,lime and acidfer just fight each other leading to no harvest,im give you a important tip though,next time when you use soil,reguardless of many that say check your runoff,disreguard,soil is a filter,our drinking water is the same filtered water,you cant get a acurite reading threw the runoff,just my opinion,to test after you harvest and flush that soil your using,keep note on how much water you use and what the ph is , do you know how to do a slurry test on your soil?
i looked it up still have about an hour until i can do it, looks like a 5 to 1 ratio in a cup and use the ph pen right into the mud. i limed all the plants pretty good but only went crazy on one, im going to report back witb the results
 
I use wood ashes to raise my Ph if necessary, since they will provide nutrients as well as raising the Ph somewhat. Lime takes a long time to work it's magic and top dressing won't really help matters deep in the soil. When the lime DOES start working, the Ph swings are going to be problematic. FFOF is fairly full of nutrients, but not to the point that that it will drag your Ph into the 4s. Is there a chance that your Ph pen/device could be reading incorrectly? Your plants look pretty healthy for having a Ph so low, in my opinion.
no i calibrate my pen, i have a blue lab and a cheap amazon one to double check because i am pretty shocked its that low, the amazon cheap pen is a little off but there both pretty close, the leaves were alot worse but i defoliated all the really bad ones. they were all twisted and curling and turning brown and crispy and then hanging on by a thread, i would touch them and they would fall off
 
i looked it up still have about an hour until i can do it, looks like a 5 to 1 ratio in a cup and use the ph pen right into the mud. i limed all the plants pretty good but only went crazy on one, im going to report back witb the results
i meant take some the soil put in glass with ro or distilled water ,shake it up and let settle about 30 min to settle,then stick your pen in the fluid not the mud,this will give a acurite ph
 
i looked it up still have about an hour until i can do it, looks like a 5 to 1 ratio in a cup and use the ph pen right into the mud. i limed all the plants pretty good but only went crazy on one, im going to report back witb the results
Slurry is a 1-1 or 2 to 1 ratio.

Dolomite lime is best added 1 tbs. per gal. soil max, I suspect you're going to have issues with all that lime you've added?
 
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That seems like an awful lot of lime to add. I'm a beginner and was curious what the ph runoff of fox farms ocean forest would typically be? I just had less than stellar results on a couple autos I just grew in it, I was real good with ph with my waterings but never have checked runoff. Is that common for runoff to drop that much?
 

JWM2

Premium Member
Supporter
I seriously doubt the ph is that low in fox farms soil. I would be shocked as the plants don’t look that bad considering. If it was in that ph range it would be much worse. Measuring runoff ph is useless. Do a slurry test as oldskool suggested. Use RO water or distilled water for the test.

If you are concerned I’d take as much of the old dirt off the root mass and repot into fresh soil. That should buy you some time and correct some of the issues. Not knowing how to properly test the ph of your soil has caused you to freak out and throw the kitchen sink at it. That’s not ideal and your plants will suffer from it.

To test runoff you need 0 ppm water and even then it will be inaccurate as some of the water will run through channels and straight out the bottom of the container. A slurry test eliminates this margin of error. Anyone who says otherwise has no idea what they are talking about.
 
did a 1 to 1 slurry on 4 of my 6 plants

the one i hit with the bunch of lime measured at a ph of 8.4 and i forgot to do the ppm

the others were;
ph6.1 @ 40ppm
ph 7.3 @ 100ppm
ph 6.5 @ 80ppm

i used distilled water with 5.7 ph @ 0ppm

i tried to take the soil samples as far down as i could to get away from the top dressing of lime, probably got the samples @ 3 to 4 inches below the surface of the soil

whats you guys' opinions on these results? do you think the soil thats deeper is a lower ph because the lime was applied at the top? and my ppms seem to be low too (the pen was set at ppm 500, i guess thats american and ppm 700 is European)

trying to figure out where i should go from here
 
I seriously doubt the ph is that low in fox farms soil. I would be shocked as the plants don’t look that bad considering. If it was in that ph range it would be much worse. Measuring runoff ph is useless. Do a slurry test as oldskool suggested. Use RO water or distilled water for the test.

If you are concerned I’d take as much of the old dirt off the root mass and repot into fresh soil. That should buy you some time and correct some of the issues. Not knowing how to properly test the ph of your soil has caused you to freak out and throw the kitchen sink at it. That’s not ideal and your plants will suffer from it.

To test runoff you need 0 ppm water and even then it will be inaccurate as some of the water will run through channels and straight out the bottom of the container. A slurry test eliminates this margin of error. Anyone who says otherwise has no idea what they are talking about.

Runoff is a tool to measure things over time. Looking for changes in trends. Many greenhouse nutrient guides i read say to check runoff for changes.

But every time i check runoff through ocean forest with a gh liquid drop test kit it shows light green to army green. 6.0-6.5. Really more like 6.3-6.5 from the color. The oyster shell and peat balance where it was intended. Normal water and fertilizer wont change that permanently. Just the readings while too much is in there.

If i have over fed a few times the buildup makes the ph read lower in the runoff.

I sure would not add lime to my pot because of 1 random runoff reading. But i might run some extra fresh water through before feeding again.
 
did a 1 to 1 slurry on 4 of my 6 plants

the one i hit with the bunch of lime measured at a ph of 8.4 and i forgot to do the ppm

the others were;
ph6.1 @ 40ppm
ph 7.3 @ 100ppm
ph 6.5 @ 80ppm

i used distilled water with 5.7 ph @ 0ppm

i tried to take the soil samples as far down as i could to get away from the top dressing of lime, probably got the samples @ 3 to 4 inches below the surface of the soil

whats you guys' opinions on these results? do you think the soil thats deeper is a lower ph because the lime was applied at the top? and my ppms seem to be low too (the pen was set at ppm 500, i guess thats american and ppm 700 is European)

trying to figure out where i should go from here
I used a new mix of soil ingredients recently and I added my usual 1 tbsp lime per gallon and now I'm constantly fighting to keep my pH under 7 this run, so with how much you put on your soil I personally don't think you're going to have very good luck.

I think your pH is going to continue to rise out of control and I'm not sure if you can reverse it? Have you tried scraping some of the top layer containing most of the lime off?
 

JWM2

Premium Member
Supporter
Runoff is only useful if you can get the water to travel through the growing medium and not around it and through channels. If it travels around the growing medium and not through it you’ll pick up mostly salt buildup on the container which will throw off the readings. Plus there’s the issue of which part of the runoff do you test? The start, after running a gallon or so through it or later? By testing the soil directly you’ll get an accurate measurement that you can then make adjustments with.

One useful tool is to buy nectar for the gods Olympus Up and Herculean Harvest and use that as a flush every couple weeks. The calcium binds to the excess nutrients and renders it null. It also flushed out excess salt buildup and delivers a boost of phosphorus to help with nutrient uptake. It’s cheap and is useful to have in your arsenal.
 
Runoff is only useful if you can get the water to travel through the growing medium and not around it and through channels. If it travels around the growing medium and not through it you’ll pick up mostly salt buildup on the container which will throw off the readings. Plus there’s the issue of which part of the runoff do you test? The start, after running a gallon or so through it or later? By testing the soil directly you’ll get an accurate measurement that you can then make adjustments with.

One useful tool is to buy nectar for the gods Olympus Up and Herculean Harvest and use that as a flush every couple weeks. The calcium binds to the excess nutrients and renders it null. It also flushed out excess salt buildup and delivers a boost of phosphorus to help with nutrient uptake. It’s cheap and is useful to have in your arsenal.

Good point about where to check runoff.

The answer is you take your measurements the same each time. I let the first half of the mixture sit for a few or more minutes and take the first 8 oz. that runs out after i pour the second half of the mixture through every time and record it.

In some fertigation tutorials they say to do it the same way each time for consistancy.
 
I use wood ashes to raise my Ph if necessary, since they will provide nutrients as well as raising the Ph somewhat. Lime takes a long time to work it's magic and top dressing won't really help matters deep in the soil. When the lime DOES start working, the Ph swings are going to be problematic. FFOF is fairly full of nutrients, but not to the point that that it will drag your Ph into the 4s. Is there a chance that your Ph pen/device could be reading incorrectly? Your plants look pretty healthy for having a Ph so low, in my opinion.
before I started adding a recommended amount of dolomite I often experienced low fives and even high fours a time or two

Not sure but suspect it may have had something to do with the particular nutrients I was using at the time
 
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