Peat and PH Consensus

Capn-Crunch

Capn-Crunch

Well-Known Member
I know peat is considered a soil less medium and has different properties than coco, rock wool, etc.
Question is, what are the peat growers PHing their water to for best nutrient uptake?
I've been going 5.8 to 6.3 but am having some issues that are PH related.
 
thumper60

thumper60

Well-Known Member
Capn-Crunch said:
I know peat is considered a soil less medium and has different properties than coco, rock wool, etc.
Question is, what are the peat growers PHing their water to for best nutrient uptake?
I've been going 5.8 to 6.3 but am having some issues that are PH related.
Click to expand...
I run promix with rain water-snowmelt never have a ph problem I gave up checking ph yrs ago.i do add 3-4 cups of lime per 3.8 bale
 
dubekoms

dubekoms

Well-Known Member
Water Alkalinity: The pH of the irrigation water is not as important as its alkalinity (CaCO3) when dealing with non-inert growing media, such as peat moss. Alkalinity is a measurement of the amount of carbonates and/or bicarbonates, or basically the amount of limestone dissolved in the irrigation water. When water has high alkalinity, it means that the water has high limestone. Every time watering occurs, more limestone is added to the growing medium, resulting in an increase in its pH overtime (Figure 1). In addition, water with high alkalinity has a large buffer capacity compared to water with low alkalinity. "Buffer capacity" refers to the ability to resist change; therefore, the higher the buffer capacity, the greater the resistance to change and the ability to lower the pH of the water.

source
 
Capn-Crunch

Capn-Crunch

Well-Known Member
Herb & Suds said:
I never ph in Pro-mix
I do foliar feed with Epsom salts in veg
Ends the early dreaded yellow leaves LOL
Click to expand...
thumper60 said:
I run promix with rain water-snowmelt never have a ph problem I gave up checking ph yrs ago.i do add 3-4 cups of lime per 3.8 bale
Click to expand...
dubekoms said:
Water Alkalinity: The pH of the irrigation water is not as important as its alkalinity (CaCO3) when dealing with non-inert growing media, such as peat moss. Alkalinity is a measurement of the amount of carbonates and/or bicarbonates, or basically the amount of limestone dissolved in the irrigation water. When water has high alkalinity, it means that the water has high limestone. Every time watering occurs, more limestone is added to the growing medium, resulting in an increase in its pH overtime (Figure 1). In addition, water with high alkalinity has a large buffer capacity compared to water with low alkalinity. "Buffer capacity" refers to the ability to resist change; therefore, the higher the buffer capacity, the greater the resistance to change and the ability to lower the pH of the water.

source
Click to expand...
Thanks for the reply's and info
 
Renfro

Renfro

Well-Known Member
I run peat based soiless mix. I started with Promix HP, used Sunshine 4 for a while and now I use Berger BM6 HP. For all of those I pH at 6.5. I tried running at 6.3 and was getting magnesium and potassium deficiencies. I first went all into my hydro thinking as thats what I had done for many years prior so I lowered the pH to 6.0, even 5.8 and it only got worse. I went to 6.5 and bam new growth looked happy and since then I have been using 6.5 in peat based soiless mixes and my plants are loving it.

So in short I believe in 6.5, if I error I error up to 6.6 never down. 6.5 - 6.7 is what I consider acceptable for my grow.
 
Capn-Crunch

Capn-Crunch

Well-Known Member
Renfro said:
I run peat based soiless mix. I started with Promix HP, used Sunshine 4 for a while and now I use Berger BM6 HP. For all of those I pH at 6.5. I tried running at 6.3 and was getting magnesium and potassium deficiencies. I first went all into my hydro thinking as thats what I had done for many years prior so I lowered the pH to 6.0, even 5.8 and it only got worse. I went to 6.5 and bam new growth looked happy and since then I have been using 6.5 in peat based soiless mixes and my plants are loving it.

So in short I believe in 6.5, if I error I error up to 6.6 never down. 6.5 - 6.7 is what I consider acceptable for my grow.
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Not that I don't believe you, but why would Promix on their website urge a water ph of 5.5 to 6.0?
I was running a ph of 6.5 to 7 so I assumed it was too high and started adjusting down because it looked like a ph issue to me.
I also checked ppm runoff and had 600 going in and 1300 in runoff so I came to the conclusion of built up nutrient
salts because of the plants were not using all the nutes because of improper ph water.
Now I'm doubting my logic, lol
 
Renfro

Renfro

Well-Known Member
No clue why they would say that, perhaps for some other kind of plant, sure led me in the wrong direction, as did the guys at AN. On the phone they said 6.2. I just know what I saw with my own eyes. Feeding at 6.5 just worked. I wish I had known that sooner it would have saved me a lot of headaches. In veg even with lower pH the plants were fine, once I kicked them into my flowering rooms with more intense light, CO2 and warmer temps they started looking pretty sad even when still vegging them for a few weeks. They needed more feed than the pH allowed them to access. Raising the pH suddenly made them happy.
 
Capn-Crunch

Capn-Crunch

Well-Known Member
UPDATE

Been keeping my PH at 5.6 to 5.8 and the plants are doing way better now. I'm also doing a feed /water or feed/ water/water and I think that's helping to keep the salts in control.
I also added a little Fulvic Acid for better nutrient uptake.
 
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T

TheHarvester

Active Member
thumper60 said:
I run promix with rain water-snowmelt never have a ph problem I gave up checking ph yrs ago.i do add 3-4 cups of lime per 3.8 bale
Click to expand...
This is the kicker with peat based medias.
Peat has a Ph of 4 to 4.5 I believe and if you don't buffer that with lime you will run into issues.
Salt build up will also mess with the Ph of your media. Like someone mentioned about it holding onto salts.
 
Kingrow1

Kingrow1

Well-Known Member
Capn-Crunch said:
UPDATE

Been keeping my PH at 5.6 to 5.8 and the plants are doing way better now. I'm also doing a feed /water or feed/ water/water and I think that's helping to keep the salts in control.
I also added a little Fulvic Acid for better nutrient uptake.
Click to expand...
Your ferts were off then not ph imo :-)
 
Capn-Crunch

Capn-Crunch

Well-Known Member
TheHarvester said:
This is the kicker with peat based medias.
Peat has a Ph of 4 to 4.5 I believe and if you don't buffer that with lime you will run into issues.
Salt build up will also mess with the Ph of your media. Like someone mentioned about it holding onto salts.
Click to expand...
ProMix is already ph'd neutral right out of the bag.
 
Kingrow1

Kingrow1

Well-Known Member
Capn-Crunch said:
The PH change alone improved the overall health of the plant before I decided to try a different feed schedule.
IMO the PH level was the issue. The ProMix suggested PH range was spot on.
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Can you re check this over future grows, either somthing is throwing ph off such as a massive calcium load in your water or it will end up being ferts like i said.

Someone mentioned alkalinity, i felt there will be more to the story in the future :-)
 
Capn-Crunch

Capn-Crunch

Well-Known Member
Kingrow1 said:
Can you re check this over future grows, either somthing is throwing ph off such as a massive calcium load in your water or it will end up being ferts like i said.

Someone mentioned alkalinity, i felt there will be more to the story in the future :-)
Click to expand...
I'm sorry you're having a hard time believing this, but again, the ProMix PH range suggestion worked, and worked well.
 
Capn-Crunch

Capn-Crunch

Well-Known Member
thumper60 said:
growing in promix is more like hydro than it is soil it likes to be flooded
Click to expand...
I agree. On my first grow I used ProMix 75% and amendments 25%. With that mix I didn't have actual soil, or peat, so I was always having to half guess what the plants needed. I'm not making that mistake again.
 
Kingrow1

Kingrow1

Well-Known Member
Capn-Crunch said:
I'm sorry you're having a hard time believing this, but again, the ProMix PH range suggestion worked, and worked well.
Click to expand...

Im not sure how you have ph'ed promix with a bit of ph up and down but aince you say this problem is now solved by this simple addition you wont be making any similar problem threads in the future... :-)
 
Capn-Crunch

Capn-Crunch

Well-Known Member
Kingrow1 said:
Im not sure how you have ph'ed promix with a bit of ph up and down but aince you say this problem is now solved by this simple addition you wont be making any similar problem threads in the future... :-)
Click to expand...
It seems I have offended your fragile ego by not agreeing with your solution to the issue I had because it was wrong.
There is no shame in being wrong, and I appreciated your suggestions to the issue.
I do however take issue when someone who thinks they are the "end all", "know all", fountain of irrefutable knowledge on cannabis cultivation
can't accept actual results contrary to their opinion.
 
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