New Grower A little PH advise please

[Heavily Medicated]

First time ever doing anything with ph. I just got my ph pen and ph down today. My plants are 4 weeks into the grow. I went in at 6.6 and the runoff was 6.9, so if I did it all right, my soil ph is about 7.2. I believe my desired soil ph is at 6.4 to 6.8 range, am I correct about this? My plan is to just lower my feeds to 6.4 and hope my soil ph begins to come down. Is this reasonable thinking, or should I do something else? Is my grow in jeopardy at the 7.2 soil ph? I am groing in promix in 3 gallon pots.

 

[namvet25]

If you lower your intake to 6.3 or 6.4 you should come out ok.

 

[Muddy]

First time ever doing anything with ph. I just got my ph pen and ph down today. My plants are 4 weeks into the grow. I went in at 6.6 and the runoff was 6.9, so if I did it all right, my soil ph is about 7.2. I believe my desired soil ph is at 6.4 to 6.8 range, am I correct about this? My plan is to just lower my feeds to 6.4 and hope my soil ph begins to come down. Is this reasonable thinking, or should I do something else? Is my grow in jeopardy at the 7.2 soil ph? I am groing in promix in 3 gallon pots.

Pro Mix has a pH of 7.0 right out of the bag. For this grow, do as Nammy has suggested. In the future you might want to consider adding some 17% aluminum sulfate to your soil mix at the rate of 4 grams per gallon of soil mix. That will lower the initial pH and after that you can feed at 6.4 and your pH will drop to about 6.2 the day after feeding, then slowly rise to about 6.6 as the soil dries out.

 

[turtle360]

If you can control your ph as such you're in a different reality than I.

good luck..........

 

[turtle360]

On another note, try measuring soil runoff then measuring using a soil probe then measure using slurry method.

https://www.dot.ny.gov/divisions/en...ces/technical-services-repository/GTM-24b.pdf

Compare the results. And please report back. Without hard scientific method we shall not prevail. Is it possible that your runoff which suggests a ph 7.2 can be corroborated by both a meter reading and a slurry test. If so you can confidently accept 7.2 as your soil ph. I have my own data, but would love to hear your results.

 

[derek420colorado]

Yes you are correct your soil pH is 7.2 and when it comes to pH I would follow anything Muddy says to the T. He is by far the most knowledgeable person on AFN about pH(and he also is like me and believes it to be very very important to growing quality cannabis)

pH is in the top 3 most important things to make sure is correct all the time because as I am sure you know if your pH is off your plant cannot absorb certain nutrients causing major problems. But it sounds like you are on the right track now and your plants should respond very quickly in a positive manner over the next week they should look happy and healthy. Sending good grow karma that way my friend

 

[turtle360]

Muddy and company may well be right. I don't doubt it. All I'm saying is I have more to learn. Check it out:

I put in about 6.6
Oct 24 water run off=5.6
Oct 27 runoff =5.4 This suggests a soil ph of 4.2 but my meter half hour after watering sitting for 10 minutes registers 4.8. I flush same night.
Oct 30 runoff=5.4-5.7 pot to pot. Meter reads 6.0.
Nov 4 runoff=5.5. meter reads 6.0-6.4 pot to pot.
The difference between 6.0 and the implied 4.4 is significant.

If I had another meter I would do a meter double check. Maybe soil ph meters aren't accurate. Muddy incidentally vouches for the meter I use. Check yours with a meter. See what it says. And please share. I'm not trying to be right. I'd just like to know.

 

[Heavily Medicated]

Muddy and company may well be right. I don't doubt it. All I'm saying is I have more to learn. Check it out:

I put in about 6.6
Oct 24 water run off=5.6
Oct 27 runoff =5.4 This suggests a soil ph of 4.2 but my meter half hour after watering sitting for 10 minutes registers 4.8. I flush same night.
Oct 30 runoff=5.4-5.7 pot to pot. Meter reads 6.0.
Nov 4 runoff=5.5. meter reads 6.0-6.4 pot to pot.
The difference between 6.0 and the implied 4.4 is significant.

If I had another meter I would do a meter double check. Maybe soil ph meters aren't accurate. Muddy incidentally vouches for the meter I use. Check yours with a meter. See what it says. And please share. I'm not trying to be right. I'd just like to know.

I do not have a soil probe ph reader, or I would do the double check and see the difference. Being new to the whole ph monitoring, the ph pen was my first investment. Will purchase an Accurate 8 when funds loosen up. For now, will just utilize the runoff method and see how it goes. From what I have gathered, when using the runoff method, you need to test the first 250ml or so out of the pot. This my be contributing to the wide variations you are getting.

 

[turtle360]

I do not have a soil probe ph reader, or I would do the double check and see the difference. Being new to the whole ph monitoring, the ph pen was my first investment. Will purchase an Accurate 8 when funds loosen up. For now, will just utilize the runoff method and see how it goes. From what I have gathered, when using the runoff method, you need to test the first 250ml or so out of the pot. This my be contributing to the wide variations you are getting.

The first 250 ml. Good point. So I've heard. I test it when most of the runoff has run off. How did you know I wasn't getting the first water? Next time I will collect the runoff more expeditiously. Although 250 ml is no small drippings. A pint. hmm.

 

[Muddy]

Any soil readings taken the same time or shortly after watering aren't going to be accurate. Always wait a day or two after watering before taking soil readings. They will be the most accurate. As the soil dries out the readings will go up, then take a drop again after the next feeding.