You were going to need to do a slurry test of your soil to determine the exact pH. If you are having pH issues, it can affect the absorption of nutrients and cause all kinds of problems. Some of these include looking like nutrient burn or nutrient insufficiency. What kind of soil are you using, what kind of light are you using, and what kind of nutrients are you using? These are all important factors, has a few things can change a whole lot of other variables.

KINSTROOM said:

A week after transplanted my plants to the 15l pot all of my plants started to get taco leaves and twisted leaves. I was told it could be produced by over feeding or heat stress, so I cuted the amount of nutes. Just to make sure I bought a Ph Tester to check If everything was ok. The tap water i've been giving since the begining has a Ph 7 but my runoff water was at 5. the soil I am using Is supposed to have a Ph 6 and it's the same soil I used in the smaller pots since the begining.
The humidity in the room is between the 40% to 60%
Temps between 19C to 25C
lights: L ED1500w phlizon (1,10 meters from the plants)
LED 1000W (70cm from the plants)

What do you recommend to get the ph up? It's been more than 2 weeks since transplant and eventhough the water i've been giving has a ph 7 the runoff is still at 5

Click to expand...

I use Dolomite lime as directed to raise and stabilize soil pH

I apologize, I just saw the earlier description of your lights. I think you have a nutrient overload, and it is not unusual for nutrients to be acidic and to cause pH issues on the acidic side, which is what you are seeing. You might need to use some sort of lime, wood ashes, or other method to increase your pH. Many buffering agents are often included in the grow medium , but it seems that you sounds like you don't have any in your mix.

If you have added lime and everything else is good, I would check your ph meter... you shouldn't have such acidic conditions if you have buffered soil.

Jimster said:

I apologize, I just saw the earlier description of your lights. I think you have a nutrient overload, and it is not unusual for nutrients to be acidic and to cause pH issues on the acidic side, which is what you are seeing.

Click to expand...

I agree, I think that's why you're seeing your runoff pH so low. You might want to start checking your PPM, if you are you didn't mention it and also for best results try adjusting your water to 6.5 instead of 7

If those were my plants I'd stop feeding nutes; I'd put some flush water through them & check the PPM and I would adjust what I fed going forward by what I found out from the PPM

KINSTROOM said:

my runoff water was at 5.

Click to expand...

Can you measure the PPMs of your runoff? That has been a very reliable indicator for me about salt buildup. I have a relatively serious soil ph probe and my soil ph goes down as the runoff ppms go up. When it hits 2400-2500, my soil ph is 3.2, and I start seeing deficiencies in the leaves.

It's worth keeping an eye on. Maybe you'll see a trend like that. I've read a couple other people say they've noticed the same thing. The most you'll do is waste some time watching it.

Imo. Stop the madness, switch to coco unless you're fully organic. I played the peat primary game for too long and products inconsistencies cost us money.

Naw mang peat and soil is tight. I found coco alone to just be a lame version of hydro, but whatever works I guess

I resolved a similar issue lately by just adding a bit of potassium silicate once (raises the ph of your mix savagely) and a weak feed or two at around 7 ph. Then back the normal 6.5 ish. It worked. I’m in promix with that plant and I just trusted that with a few high ph feeds it would buffer out. It did.. . I’m not a rocket scientist but I figured higher ph in the top would mean higher ph out the bottom. Didn’t fix the problem instantly tho by any means.
I’m finding using ph products on the reg to frig with the soil. If it’s close enough after mixing nutes I trust the buffering qualities of the medium and don’t tweak. That’s helped a lot

I have grown with promix for the last 35 years or more and I really can't say anything bad about it. I've seen a lot of people have problems with Coco, especially watering problems. That is one thing I can say for the promix, it seems to really eliminate any problems with over-watering, or at least that is what I have seen in my experience. Any of them can go wrong if they are not setup properly.

UncleRomulus said:

I’m finding using ph products on the reg to frig with the soil. If it’s close enough after mixing nutes I trust the buffering qualities of the medium and don’t tweak. That’s helped a lot

Click to expand...

I stopped ph'ing my nutrient solution after I saw how my runoff PPMs correlated to salt buildup and soil acidity. Ph-up products contain salts. (They contain nutrients, but the label doesn't show it because it's not sold as a fertilizer.). So, I was creating a vicious cycle. The stronger the nutrient solution, the more salts built up in the soil. The stronger the nutrient solution, the more ph-up I had to use... which added to the strength of the nutrient solution. The more salts in the soil, the more acidic it became... leading me to use more ph-up -- putting more salts in the soil.

The runoff ppms were the key for me. When I found the fertilizer strength (and runoff volume) which didn't send my runoff above 2000ppm (2400-2500 is where lockout occurs for me. I've read someone else say the same thing.), I didn't need a lot of ph-up, which led me to think the soil's buffers must have enough gravity to pull the nutrient solution that much. So, I stopped phing the nutrients. A little ph-up (when the nutrient solution is properly strengthed) wouldn't hurt anything. But, it seemed like a pointless activity because the soil pulls the nutrients to its ph, not the other way around -- unless the nutrients are strong and build up over time. Which ph-up exacerbates.).

No more calibration solutions. No more storage solution. No more probe cleaning.

BTW: You don't even need calibration solution for TDS meters either. Mix one gram of ordinary salt (in a shaker, on your kitchen table) to one liter distilled water. By definition, that's 1000ppm. If you were in a lab where measurements have to be precise, maybe certified calibration solutions are necessary. But, growing this is close enough.