Coco coir pH at 7.0 - watering at 6.0

masho95

masho95

Active Member
So I'm on day 59 of flower, but only have recently purchased a soil pH tester. Since I started testing the coco pH has been around 7. Just retested this morning and had 6.8, 7.0, and 7.1 between my 3 plants. Using Dr. Earth amendments and tap water.

I've watered at 6.0 pH for at least the last 3 waterings and haven't seen a change. I keep some water in 5 gal buckets with air stones pumping air into it constantly to dechlorinate and keep it fresh. After i pH the water to 6.0 the next day it will retest at 7.5 pretty much how it comes out of the tap. Water report for my city states they aim for it to be delivered at 8.0 pH with no chloramines just chlorine gas, bleach, sodium carbonate, sodium bicarbonate, sodium polyphosphate, and monosodium phosphate.

Is it normal for the pH to go back to 7.5 after a day of just sitting there? I'm afraid the same is happening in my plant medium where I water to 6.0 and it's raising on it's own to 7.0 in the medium like when I test it. So for future grows would you suggest using the same water or a new source? Thanks.
 
coreywebster

coreywebster

Well-Known Member
Stop bubbling your water it changes the ph, something along the lines of the extra o2 pushing out the co2 and raising the ph
Don't rely on a soil ph tester to be accurate.
 
masho95

masho95

Active Member
xtsho said:
How do the plants look? Are they healthy?
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Plants are just ok I think. First grow so multiple growing pains on my first attempt. Although it's coco I overwatered a lot early in their life. I started with seeds in 5 gal fabric pots and didn't realize how important transplanting would be for healthy growth. Also had been under a cheap amazon blurple led for most of their life. Just upgraded to a SF2000 for my 32x32x60 tent. A little too intense I think for the top colas as some of the fan leaves got crispy. I couldn't raise the light any higher but ended up removing the 3 inch platforms the fabric pots were on in order to get them a little farther from the lights. So I think I had poor veg growth from all the issues, small stem size, had some extra stretch, and buds are small. But I'll be happy just to be able to yield something off these and definitely have learned a lot through this while process.20200211_052645.jpg
 

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coreywebster

coreywebster

Well-Known Member
masho95 said:
For $150 it better be accurate lmao. It's a Blue Labs soil pH tester not a cheap multi function probe unit.
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Fair enough.


What ever it is your feeding them either isn't enough or not keeping up. Looks like they are robbing Peter to pay Paul.

Coco looks way too dry, is that part of the plan with this organic idea?
 
masho95

masho95

Active Member
coreywebster said:
Fair enough.


What ever it is your feeding them either isn't enough or not keeping up. Looks like they are robbing Peter to pay Paul.

Coco looks way too dry, is that part of the plan with this organic idea?
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Thought that maybe the 7.1 pH of the coco was locking out nutes. They were just watered yesterday morning. Top soil is probably starting to dry but pots are still heavy.
 
TintEastwood

TintEastwood

Well-Known Member
Do the best you can to finish and harvest what you have.

Unless growing 6ft trees, 3gallon is the max I use for indoor.
www.cocoforcannabis.com

Growing Cannabis in Coco Coir with High Frequency Fertigation - Coco For Cannabis

Learn how to unlock the magic of growing cannabis in coco coir with high frequency fertigation! Guide to feed and water cannabis in coco like a pro!
www.cocoforcannabis.com www.cocoforcannabis.com

Know your coco. The PH of the coco can get jacked up if mistreated - flushing by dumping gobs of high PH plain water thru the coco is one way.
www.cocoforcannabis.com

Coco Coir Bricks - How to Prepare and Buffer Coco Coir - Coco For Cannabis

This tutorial covers the process of selecting, preparing & buffering coco coir. Includes perlite ratios & tips to make coco the best media for cannabis
www.cocoforcannabis.com www.cocoforcannabis.com
 
curious2garden

curious2garden

Well-Known Mod
Staff member
masho95 said:
Plants are just ok I think. First grow so multiple growing pains on my first attempt. Although it's coco I overwatered a lot early in their life. I started with seeds in 5 gal fabric pots and didn't realize how important transplanting would be for healthy growth. Also had been under a cheap amazon blurple led for most of their life. Just upgraded to a SF2000 for my 32x32x60 tent. A little too intense I think for the top colas as some of the fan leaves got crispy. I couldn't raise the light any higher but ended up removing the 3 inch platforms the fabric pots were on in order to get them a little farther from the lights. So I think I had poor veg growth from all the issues, small stem size, had some extra stretch, and buds are small. But I'll be happy just to be able to yield something off these and definitely have learned a lot through this while process.View attachment 4476966
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Those are not ok. If you are in pure coco or coco perlite you need to feed and water daily. You shouldn't let coco completely dry out. Once plants have established roots you can't overwater in coco.

PS I run my water and nutrient at 5.5 to 6.0 with 5.8 being what I shoot for, good luck. I also never bother to measure coco's pH or my run off's pH or TDS/EC. I just run a good amount of water to flush any excess salts out once every 2 weeks.
 
masho95

masho95

Active Member
curious2garden said:
Those are not ok. If you are in pure coco or coco perlite you need to feed and water daily. You shouldn't let coco completely dry out. Once plants have established roots you can't overwater in coco.

PS I run my water and nutrient at 5.5 to 6.0 with 5.8 being what I shoot for, good luck. I also never bother to measure coco's pH or my run off's pH or TDS/EC. I just run a good amount of water to flush any excess salts out once every 2 weeks.
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They are organically amended for food. I'm not sure they could be watered more without having the pots constantly soaked.
 
Teag

Teag

Well-Known Member
masho95 said:
So I'm on day 59 of flower, but only have recently purchased a soil pH tester. Since I started testing the coco pH has been around 7. Just retested this morning and had 6.8, 7.0, and 7.1 between my 3 plants. Using Dr. Earth amendments and tap water.

I've watered at 6.0 pH for at least the last 3 waterings and haven't seen a change. I keep some water in 5 gal buckets with air stones pumping air into it constantly to dechlorinate and keep it fresh. After i pH the water to 6.0 the next day it will retest at 7.5 pretty much how it comes out of the tap. Water report for my city states they aim for it to be delivered at 8.0 pH with no chloramines just chlorine gas, bleach, sodium carbonate, sodium bicarbonate, sodium polyphosphate, and monosodium phosphate.

Is it normal for the pH to go back to 7.5 after a day of just sitting there? I'm afraid the same is happening in my plant medium where I water to 6.0 and it's raising on it's own to 7.0 in the medium like when I test it. So for future grows would you suggest using the same water or a new source? Thanks.
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I'm no expert but have grown with coco and organic amendments mixed in a couple times. I assume you saw Mr Canuck Grows on Youtube.

I think your water is fine if you made it this far. It appears you didn't amend enough or fell behind on top dressing. Looks like it ran into a nitrogen shortage.

As far as PH of the medium. You need to water closer to a PH of 5.0 for maybe two watering to get a faster change. But your treating this coco like a living soil so you really shouldn't need to worry about the PH of the medium (unless you put too much dolomite lime or oyster shells in like Mr Canuck). Are you brewing compost teas or using a microbial innoculant like Tribus? If not then its going to be tough to grow this way IMO.

P.S.
I would switch to soil or watering coco with nutrients for the next grow. GL
 
masho95

masho95

Active Member
Teag said:
I'm no expert but have grown with coco and organic amendments mixed in a couple times. I assume you saw Mr Canuck Grows on Youtube.

I think your water is fine if you made it this far. It appears you didn't amend enough or fell behind on top dressing. Looks like it ran into a nitrogen shortage.

As far as PH of the medium. You need to water closer to a PH of 5.0 for maybe two watering to get a faster change. But your treating this coco like a living soil so you really shouldn't need to worry about the PH of the medium (unless you put too much dolomite lime or oyster shells in like Mr Canuck). Are you brewing compost teas or using a microbial innoculant like Tribus? If not then its going to be tough to grow this way IMO.

P.S.
I would switch to soil or watering coco with nutrients for the next grow. GL
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Yes, started with the idea from Mr. Canucks Grow on YouTube. As far as top dressing that was done every 30 days at the start of the grow and I eventually started amending more often at every 3 weeks when I started to notice the plants getting hungry earlier. This last amend I did reduce the amount they got because wanted to getting them flushing early as the timing was going to interfere with harvest. I'm about a week out from hitting the 10 week flower mark. They did get a couple compost teas I brewed up but never heard of Tribus I'll have to look that up, thank you.

Thank you all for the responses I truly appreciate them all!
 
MedMonkey

MedMonkey

Active Member
masho95 said:
Water report for my city states they aim for it to be delivered at 8.0 pH with no chloramines just chlorine gas, bleach, sodium carbonate, sodium bicarbonate, sodium polyphosphate, and monosodium phosphate.
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Do you know how much total sodium is in your tap water? I had many issues before I realized the tap water here has way too much
 
masho95

masho95

Active Member
MedMonkey said:
Do you know how much total sodium is in your tap water? I had many issues before I realized the tap water here has way too much
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Sodium Bicarbonate (Baking Soda) NaHCO3 = Sodium Bicarbonate addition is adjusted so that there is an alkalinity after treatment of 25 - 30 mg/L

Sodium Carbonate (Soda Ash) Na2CO3 = The raw water pH is approx. 7.0 and after treatment with Sodium Carbonate and Sodium Bicarbonate the finish water pH is approx. 8.0. This pH adjustment along with an increase in alkalinity reduces the water’s corrosivity. Usage is approximate 50 - 140 pounds per day.

Sodium Hexametaphosphate (Polyphosphate) = Usage is approximately 50 - 80 pounds per day and is adjusted to maintain a finish water phosphate dose (when combined with Monosodium Phosphate) of approximately 2.0 mg/L total phosphate and 1.0 mg/L orthophosphate.

Monosodium Phosphate (Orthophosphate) NaH2PO4 = Usage is approximately 50 - 80 pounds per day and is adjusted to maintain a finish water phosphate dose (when combined with Sodium Hexametaphosphate) of approx. 2.0 mg/L total phosphate and 1.0 mg/L orthophosphate.

As for what is too much, or the exact amout even I couldn't say.
 
F

Federucci

Well-Known Member
I am an old fart but I will tell you that my tap water rises from 7.3 to 8 in a day or so. I believe that there is some process where it reacts with the atmosphere in which some compounds gassed out resulting in higher pH than what came out of the tap. Your experience mimics mine almost exactly, resulting in me going for RO. You can also gas out you tap water until it's stable and then pH and see if it holds. I hope this helps in any way.
 
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