Hey guys, I have an issue I haven’t had before, when I watered last time, my runoff EC was good but PH was a bit high. I watered/fed them at 1.4 EC and PH at 5.9. PH came out at 6.5. This time I fed at 1.4 EC and dropped PH to 5.6, runoff was 1.2EC at 6.5 again. I ran 4 extra gallons thru the last two to flush and reset media, but PH rose to 6.6 in the runoff. Anybody have an idea why??? I’m in Promix BX Mycho and Fungi, with added perlite running Jacks 321 nutes with an occasional shot of humic/fulvic and cal mag. I’m in a 6x8 grow room with atmosphere dialed in tight! Light is Szhlux 840 watt set at 50%, 30 inches from tops. Ladies are growing and healthy but I need to get a handle on this ph rising. Any ideas welcome, thanks!! I didn’t post pics because they aren’t showing anything wrong, just want the ph where it should be.
For what it’s worth. I helped a guy out 6 months ago with this issue. More details are explained here.
Nevertheless, the majority of the people with this issue said they ignored the runoff pH but kept a 6.5 pH to their feed water going in only because their plants never showed any signs of a pH issue or deficiencies whatsoever.
In conclusion, against my better judgment I told the person I was helping to simply ignore it until something happens. He continued to water at 6.5 and apparently the pro mix soil somehow buffered to the 6.5 regardless of the runoff pH
It’s one of those things you can’t give a real explanation to but ignoring it seems to work best.
(Now’s the Time everybody can come in and tell me I’m wrong)
My advice ignore it see what happens.
Not sure I understand the Promix buffered to 6.5 no matter the runoff. The runoff numbers are what I’m talking about, or did you mean no matter the ph going in? No matter what I’ve put in so far, it comes out 6.5. That’s a bit high for Promix, I just can’t figure how Promix would buffer to 6.5 when the Promix is ph’d to 5.8-6.1. I took a slurry of the promix when I potted it and it was 5.9. They are eating good, I wonder if them eating the Nutes at the rate they are would affect ph?….
What I’m saying is ignore the runoff pH.
That’s a very bold statement but you’ve got hundreds of people that have the same problem that you do with the out of range runoff number. The solution seems obvious since no one is having any problems with their plants.
Ignore it
If your desired pH is 5.9, 6.1 whatever just keep pH in your water properly going in and ignore the pH runoff numbers
By the way your plants look fantastic 
I found another article on that very thing, it said to treat it just like hydro, ph in at 5.2 and it would let the media drag it up thru their range. I get what you’re saying about ignore it but it’s steady climbing, I now think it is due to bicarbonate in the water building up in the media. I’m goons ignore it on a few and drop in ph to 5.2 or so on a few and we will find out which is better! lol Thank you for the advice and article, it does shed some light on the subject. Carry on…… now I’m singing Kansas in my head and can’t stop!
Thank you! They are Northern Lights and Blackberry Moonrocks. Funny, the BM numbers are fine, 1.4 and 5.9 and they are getting same Nutes as the NL, that’s why I wondered if it was due to their feeding habits.
Nice set up your loaded for bear. What is on your leaves is that water? Maybe it’s my eyes
It’s residue, they were IPM sprayed the day before.
IPM? Not sure what that is
Pest management?
Yes, preventitive maintenance.
Remember less is more. Watch the tips on your leaves
Tips are green, no burn. I’m pushing these a bit harder than I usually do, but I’m not trying to fry them. They are pigging out so far with no sign of burning. Nute burn isn’t as common as most think, most time it’s actually K getting locked out that causes tip burn, over feeding causes that lockout.
I know it seems counter intuitive, but I agree 99% with @Lostgirl. Runoff PH is NOT the same as soil PH. Soil PH is created by the dirt, moisture in the dirt at that time, specific nutrients in the soil at the moment the reading is taken, and probably much more that I don’t understand. When you water, Some of those nutes from the water are trapped in the soil and others are washed out with the runoff. By the time you measure the runoff It will have a different composition and thus PH than soil. Not to mention just the fact that the runoff is not in contact with the soil anymore can change the PH. Your runoff PH can also change based on small changes in you watering habits or the plants usage.
That said, watering with water that is too acidic to try to average things out can change the soil PH since it is out of range before reacting to the soil rather than after as in the case of runoff. That can reduce the availability of nutes, causing more buildup, causing more issues. If there is a PH problem the answer is almost always water with properly PH’ed water. I have seen in my research that if there truly is a problem with soil PH a little gypsum watered through the soil can help, but I have never needed to try this personally. Water with normally ph’ed water and if the plants are happy don’t sweat it.
Yeah, I’m probably getting too far ahead. I just try and keep things dialed in, sometimes mabey too much! I always thought the best way to fix something was to prevent it from happening in the first place. I know they will be fine, just can’t love them tooo much. I had a few small rust spots on some fan leaves and they have stopped since I dropped ph going in, I was just baffled at runoff not changing, but I know it’s mostly just the buffering in the media that’s doing it. I’ll keep on keepin on with em! Thanks to all !
Tip burn is the way the plant communicates telling you this is what I like as far as nutrient intake.
I, like yourself love to push my plants. I push them till I see the tip burn and then I usually back off 50 EC and keep it there for a while.
This is how I interpret and have been tip burn.
Having assisted in this problem before with the offset so to speak pH I actually went into yet another form and found the issue with promax. It’s incredibly strange there are some explanations to be honest that go over my head. Yet one thing everyone agrees on is that there’s absolutely nothing wrong with their plants.
It’s almost as if the soil is chelted (like Advanced Nutrients pH perfect) what it does is open up availability to nutrients at a pH range much lower and higher range than standard. This would totally explain it.
I believe if I were having this problem personally I would be on the phone with the manufacturer of pro-mix to see exactly what the nature of the beast is.
Yes there’s a funky pH runoff number that alarms us as growers. This pro Max soil is doing just that. The fact that there is little to no one having an issue I kind of resort back to the old saying. If it ain’t broke don’t fix it
I invested in a 19 $ Probe At STaffers of Kissel hill no more testing run off for soil ph. ppm I sill do at the beginning middle and end. I grow in soil with dry amendments, it’s ok as a reference but I don’t live by it. I don’t push the plants though either , I just leave them do there thing.
ged ged yah thanks for sharing your grow. Happy 4th
I never considered chelation in the media, but I think you def have something there!If it were that out of whack, the leaves would be talking to me by now. I think I’ll give Troy at Promix a call and bend his ear! Happy 4th to all!
Right on 