WOW! BAD pH issues!!

tstick

tstick

Well-Known Member
My plants were growing like Vikings....and then, all of a sudden, they started to stall out and turn yellow. I knew it wasn't nutrient deficiency, so I figured there must be some kind of lockout happening. I normally grow with the standard FFOF and FFHF soils that I usually amend with some organic ferts (4-4-4) and worm castings, rice hulls, perlite, some coco coire to lighten it up.

My tap water is 7.0. I always use a few drops of ph Down to bring it into the 6.0-6.5 range.

I hadn't thought to do a check of the runoff...until just a little while ago...OMG.....The runoff pH was somewhere in the 4.0 range! I use the General Hydroponics pH test drops and the test vile of runoff water turned bright red immediately! FUUUUUUUCCCCKKKK! :( "Well, there's yer problem!" :) Obviously, something that I added to the FF soil was very acidic. It must have been in the 4-4-4 organic ferts I added. Everything else should have been fairly neutral.

So, I did a thorough flush with some water and added pH Up. The runoff is starting to come up now, but it's still in the 5's. I'll wait a day or two and repeat the process until I can get the runoff into an acceptable range.

Thank God I didn't panic and run for the Cal-Mag! ;)
 
tstick

tstick

Well-Known Member
What I don't get is why the plants started out growing so well in the same, exact soil mix!
harris hawk said:
never have checked "ph" in all my years of cultivation - don't go down the "rabbit-hole" - alway had great yields
Click to expand...
Yep same here! I never bothered with any of that crap. But something was definitely going wrong and I couldn't figure it out. But, man...~4.0 pH is extremely acidic. Maybe if I was growing blueberries....')
Kushash said:
Is it a new bag of soil or are you amending previously used soil?
Click to expand...
New. But a lot of what I amended it with was just "fluff" -rice hulls, coco coire, perlite...so I always add some extra ferts to compensate for that extra neutral bulk that doesn't contain anything.
 
tstick

tstick

Well-Known Member
And one more weird thing is that, when I checked the root ball on one of the plants that turned out male, it (the root ball) was also very healthy.

I have the HLG 300 red spec at 18" and dimmed down to somewhere around 50% so it's not the light that's doing it. The temps are right. The RH is ok.....It's a first for me in all my years of doing this!
 
Kushash

Kushash

Well-Known Member
tstick said:
What I don't get is why the plants started out growing so well in the same, exact soil mix!

Yep same here! I never bothered with any of that crap. But something was definitely going wrong and I couldn't figure it out. But, man...~4.0 pH is extremely acidic. Maybe if I was growing blueberries....')

New. But a lot of what I amended it with was just "fluff" -rice hulls, coco coire, perlite...so I always add some extra ferts to compensate for that extra neutral bulk that doesn't contain anything.
Click to expand...
I don't use the method you are using to determine PH. I use a cheap bluelabs soil probe, slurry tests and plant observation. I keep an eye on runoff for color and EC because I re-amend soils and sometime run into a buildup and need to leach. I have definitely run into bags of ffof that have had PH issues show up in early flower. Most of the time it shows as a calcium lockout in early flower when calcium is in high demand, but PH issues can sometimes show weird symptoms. Top dressing with dolomite lime has worked for me in those situations. When it looks like a calcium issue from lockout or deficiency, Dolomite can cover both areas if the person isn't sure and with ffof being a fairly acidic soil I find it a safe addition in early flower. I'm off for a while, probably a good idea to show some pics of the issue.
 
crimsonecho

crimsonecho

Well-Known Member
if you really wanna learn the ph of your medium you should do a slurry test at least. i dont think runoff ph will be meaningful in an organic grow. with salts it may mean something but all you are flushing out of your soil is decaying organic matter which is always acidic but its also the plants food. well i hope you resolve your issue soon.
 
tstick

tstick

Well-Known Member
I also took a spoonful of the soil and added water to it and let the soil separate from the water and then drew up some of the clear liquid and used the drops to test it. -same deal.

I don't know exactly what the pH is, but I can see that the runoff is at least an indication of what's probably happening. I've never had a runoff show this low of a pH before. If raising it up to a higher level doesn't bring the plants back to health, then I'll probably just scrap this grow and start over.
 
Modern Selections

Modern Selections

Well-Known Member
harris hawk said:
never have checked "ph" in all my years of cultivation - don't go down the "rabbit-hole" - alway had great yields
Click to expand...
Just because it worked in your garden does not make it a scientific fact. Imagine your yield if you got your pH in check?

To the OP, don't spend too much time on pH runoff. Sounds like you flushed the plant out and if you keep your pH input correct the soil will balance itself out.

Most likely you got a hot bag of FFOF. Last year I had a bag of strawberry fields fox farms burn the snot out of my plants right out of the bag. It happens.
 
H

harris hawk

Well-Known Member
Modern Selections said:
Just because it worked in your garden does not make it a scientific fact. Imagine your yield if you got your pH in check?

To the OP, don't spend too much time on pH runoff. Sounds like you flushed the plant out and if you keep your pH input correct the soil will balance itself out.

Most likely you got a hot bag of FFOF. Last year I had a bag of strawberry fields fox farms burn the snot out of my plants right out of the bag. It happens.
Click to expand...
Good point about yields
 
DoubleAtotheRON

DoubleAtotheRON

Well-Known Member
This is kinda my field of expertise. I had a widespread problem going on with my commercial op. And on the commercial side, you just can't skimp when it's your income. So, I bought an Apera 8500s Direct Soil Probe. It's got a Swiss glass tip probe (which lasts about a year), and it gives an instant digital reading down to the 100th. I tested my crop, and sure enough, I was in the mid 4's in soil. Flushed the whole room in 11 (yeah, I know it sounds crazy) to get the soil to buffer back up to 6.5 After testing many things with it from soil, to vinegar, wine, coffee, and my own unine (8.3) I have had plenty of experience with it. I can def tell you that the top layer, the root zone, and the runoff are all totally different. It wasn't cheap by any means.. like $700, but it saved my crop. Had I relied on slurry or runoff alone, I would be chasing my tail still. Im not asking you to spend a fat stash to be accurate, just letting you know that runoff, and slurry tests are not accurate as to what is happening IN the root zone where everything is getting absorbed. You say you didn't get locked out, but if your PH is in the 4's... you're locked out.IMG_5280.jpg
 
Kushash

Kushash

Well-Known Member
DoubleAtotheRON said:
The above pic shows 6.86 after a fresh feeding in the root zone, 24 hours later, it might drop to 6.4, and will constantly drop as you approach the dry back. By the time you need to feed again, you might be at 6. This is why when I feed, I'll feed in at 7.3, buffers at 6.8, and absorbs in the "Golden Zone" at 6.5
Click to expand...
Do your instructions have any information about using ro or distilled water the day before testing?
My low end blue lab pen instructions include this:

Moisture level/raw water If the sample you are wishing to measure is dry, add RO water or distilled water to moisten. Ideally wait 24 hours before you take a measurement. NOTE: If you add tap water, you will influence the soil pH reading based on the pH of the tap water/

I always let the soil dry then water with ro the day before testing.
 
DoubleAtotheRON

DoubleAtotheRON

Well-Known Member
Kushash said:
Do your instructions have any information about using ro or distilled water the day before testing?
My low end blue lab pen instructions include this:

Moisture level/raw water If the sample you are wishing to measure is dry, add RO water or distilled water to moisten. Ideally wait 24 hours before you take a measurement. NOTE: If you add tap water, you will influence the soil pH reading based on the pH of the tap water/

I always let the soil dry then water with ro the day before testing.
Click to expand...
Yes, Apera recommends that only if the medium is too dry, but I never let it get to that point. I’ve had some hydrophobic spots in plants, so I’d take my measurements in a moist area.
 
tstick

tstick

Well-Known Member
DoubleAtotheRON said:
This is kinda my field of expertise. I had a widespread problem going on with my commercial op. And on the commercial side, you just can't skimp when it's your income. So, I bought an Apera 8500s Direct Soil Probe. It's got a Swiss glass tip probe (which lasts about a year), and it gives an instant digital reading down to the 100th. I tested my crop, and sure enough, I was in the mid 4's in soil. Flushed the whole room in 11 (yeah, I know it sounds crazy) to get the soil to buffer back up to 6.5 After testing many things with it from soil, to vinegar, wine, coffee, and my own unine (8.3) I have had plenty of experience with it. I can def tell you that the top layer, the root zone, and the runoff are all totally different. It wasn't cheap by any means.. like $700, but it saved my crop. Had I relied on slurry or runoff alone, I would be chasing my tail still. Im not asking you to spend a fat stash to be accurate, just letting you know that runoff, and slurry tests are not accurate as to what is happening IN the root zone where everything is getting absorbed. You say you didn't get locked out, but if your PH is in the 4's... you're locked out.View attachment 5339204
Click to expand...
Actually I indicated that I thought I DID get a lockout. I knew it couldn't be a deficiency because the soil has plenty of nutrients in it that could not have been depleted at this point in the grow. So, the nutrients are in there, but can't be absorbed because of the low pH. I have now amended the mix with a TBSP-per-gallon-of-soil of horticultural lime and repotted the two female plants into 4-gallon containers and watered them in with water that has a raised pH.

I'd love to have a pH meter like that, but I don't even spend that much on my lights, so it wouldn't be feasible for me. I may not know the EXACT pH from the tests that I've done, but I know enough to know that if ANY kind of reasonable test is showing that drastic of a level (~4.0), then it's likely what's causing the problem ....just deductive reasoning. I did the same tests AFTER flushing and repotting with amended soil and now the range is closer to 6.5. So, now it's just a matter of waiting to see if the plants bounce back or not.
 
Gemtree

Gemtree

Well-Known Member
I always heard that ramping up the microbes helps. Do you use tea at all? Might get you the rest of the way. I tried ffof way back and had the same problem so switched to coco
 
tstick

tstick

Well-Known Member
Sfpyro420 said:
what kind of coco are you using
Click to expand...
I amend my soil mix with Mother Earth Coco Loco -which also has perlite in it....and is SUPPOSED to be rinsed. I've always used coco in my soil-less soil mixes and i've pretty much always mixed the soil the same way for at least the last 10 years or so. Well....;lesson learned and hopefully I can salvage the grow. The jury is still out on the other three plants...waiting to see pre-flowers...but everything has been stunted by this pH ordeal, so it's probably going to take a few weeks to re-set. UGH! *shrugs*
 
You must log in or register to reply here.
Top