How to alter the base pH of my medium?

[tokeycones]

Hey guys, so i water daily to runoff just started twice per day , if it goes in at 5.8 it comes out at 6.5-6.6 which tells me the coco may be buffering it to this which is no good and could be the reasoning behind a few deficiencies i'm seeing.

 

[Old Salt]

The pH and TDS of run off from coco is immaterial. The plants will change them, as will the nutrient solution's passage through the coco. Adding chemicals to modify the pH of the run off will adversely affect your plants! It's the pH of the nutrient solution that matters.

I use Canna Coco Bricks as they are the highest quality that I found.
To prepare my 70% coco / 30% perlite substrate for use I:
- Expand the Canna Coco Bricks using pH 5.8 water
- Mix in the appropriate amount of perlite
- Flush with water and 0.3ml/l CALiMAGic at pH 5.8 until the runoff is below pH 6.5
- - (this usually takes about double the volume of the coco/perlite substrate)
- Let the substrate drain for 24 hrs
- The coco/perlite substrate is now ready for use

To re-use the substrate I start during the flush prior to harvest:
- Water four days with Flora Kleen at 1ml/l pH 5.8 twice per day
- Water four days with Flora Kleen at 0.5ml/l pH 5.8 twice per day
- Water four days with CALiMAGic at 0.15 ml/l pH 5.8 twice per day
- *** harvest my plants, recover the root balls, and shake off as much of the substrate as possible ***
- Store the coco/perlite in a Rubbermaid tub until re-use
- Mix 20% new coco/perlite with the used substrate
- Re-start the cycle...

I re-use the substrate up to four times before starting with fresh substrate.

During my plants life-cycle I maintain the following pH levels for my nutrient solutions:
- seed through aggressive vegetation - pH 5.8
- stretch (from the flip to first flowers) - pH 6.0
- flowering until the flush - pH 6.2
- flush - pH 5.8


Use an accurate pH pen to measure the pH of your nutrient solutions. The minimum accuracy I recommend is ±0.05pH. This is how close the sensor and electronics measure the pH compared to its true value. The precision, also called resolution of the instrument is how close the reading on its display comes to the measured value. This is almost always ± the least significant digit of the display. If it's not given, use that value. An instrument with a given accuracy of ±0.1 pH, and display with a single digit following the decimal point with no given precision has a displayed reading ±0.2pH. A reading of 6.0 means the true pH of the solution is between 5.8 and 6.2. An instrument with an accuracy of 0.05pH and a given precision of 0.01pH will have a reading between 5.94 and 6.06 for the same nutrient solution. I've used cheap instruments with great success at accuracies of 0.05pH and precisions of 0.01pH. Currently I'm using a HM Digital pH-200 which has a accuracy of 0.02pH and precision of 0.01pH for a reading of ±0.03pH, or for a nutrient solution with a true pH of 6.0 will display between 5.97pH and 6.03pH.

The key to getting an accurate pH reading is to check the calibration of your instrument before each use. I use Growtek's pH Buffer #7. I recalibrate if the reading is outside the range of pH 6.97-7.03. Every month I re-calibrate the instrument at pH4.0 followed by pH 7.0. This ensures that the pH of my nutrient solutions is as accurate as possible.

 

[SamSmith]

How do i change the base ph of my medium?

Short answer, you don't.

Most experienced coco guys don't sweat runoff numbers with drain to waste.

 

[tokeycones]

[/QUOTE]Thanks man this is very good info i appreciate it alot
, after afew tests i just ran i've come to the conclusion my pen is out. It only alarmed me when i saw 6.8 in runoff as 5.8 going in 1.0 is a huuuge gap. But i now realise my pen has had it and it's drifting between uses. New Bluelab pen arriving in the morning i think that is an accuracy of 0.05 as you suggest but i may be mistaken. got the full care kit so im going to keep this one 100%

 

[seriousburner]

The pH and TDS of run off from coco is immaterial. The plants will change them, as will the nutrient solution's passage through the coco. Adding chemicals to modify the pH of the run off will adversely affect your plants! It's the pH of the nutrient solution that matters.

I use Canna Coco Bricks as they are the highest quality that I found.
To prepare my 70% coco / 30% perlite substrate for use I:
- Expand the Canna Coco Bricks using pH 5.8 water
- Mix in the appropriate amount of perlite
- Flush with water and 0.3ml/l CALiMAGic at pH 5.8 until the runoff is below pH 6.5
- - (this usually takes about double the volume of the coco/perlite substrate)
- Let the substrate drain for 24 hrs
- The coco/perlite substrate is now ready for use

To re-use the substrate I start during the flush prior to harvest:
- Water four days with Flora Kleen at 1ml/l pH 5.8 twice per day
- Water four days with Flora Kleen at 0.5ml/l pH 5.8 twice per day
- Water four days with CALiMAGic at 0.15 ml/l pH 5.8 twice per day
- *** harvest my plants, recover the root balls, and shake off as much of the substrate as possible ***
- Store the coco/perlite in a Rubbermaid tub until re-use
- Mix 20% new coco/perlite with the used substrate
- Re-start the cycle...

I re-use the substrate up to four times before starting with fresh substrate.

During my plants life-cycle I maintain the following pH levels for my nutrient solutions:
- seed through aggressive vegetation - pH 5.8
- stretch (from the flip to first flowers) - pH 6.0
- flowering until the flush - pH 6.2
- flush - pH 5.8


Use an accurate pH pen to measure the pH of your nutrient solutions. The minimum accuracy I recommend is ±0.05pH. This is how close the sensor and electronics measure the pH compared to its true value. The precision, also called resolution of the instrument is how close the reading on its display comes to the measured value. This is almost always ± the least significant digit of the display. If it's not given, use that value. An instrument with a given accuracy of ±0.1 pH, and display with a single digit following the decimal point with no given precision has a displayed reading ±0.2pH. A reading of 6.0 means the true pH of the solution is between 5.8 and 6.2. An instrument with an accuracy of 0.05pH and a given precision of 0.01pH will have a reading between 5.94 and 6.06 for the same nutrient solution. I've used cheap instruments with great success at accuracies of 0.05pH and precisions of 0.01pH. Currently I'm using a HM Digital pH-200 which has a accuracy of 0.02pH and precision of 0.01pH for a reading of ±0.03pH, or for a nutrient solution with a true pH of 6.0 will display between 5.97pH and 6.03pH.

The key to getting an accurate pH reading is to check the calibration of your instrument before each use. I use Growtek's pH Buffer #7. I recalibrate if the reading is outside the range of pH 6.97-7.03. Every month I re-calibrate the instrument at pH4.0 followed by pH 7.0. This ensures that the pH of my nutrient solutions is as accurate as possible.

Yup it only matters how it goes in not how it comes out

 

[Aroxol]

Quick question for the group. Have any of you amended coco with other nutrient bearing ingredients - and if so - did you find that your medium’s pH still didn’t matter? I normally run coco/perlite or coco/growstones, but am getting much more creative with my blends these days. As such, I’m doing fairly in-depth runoff tests to ensure appropriate pH levels similar to soil. Just wondering if any of you have deviated away from basic coco recipes and still run successful without concern for pH? Thanks.

 

[PE636]

Quick question for the group. Have any of you amended coco with other nutrient bearing ingredients - and if so - did you find that your medium’s pH still didn’t matter? I normally run coco/perlite or coco/growstones, but am getting much more creative with my blends these days. As such, I’m doing fairly in-depth runoff tests to ensure appropriate pH levels similar to soil. Just wondering if any of you have deviated away from basic coco recipes and still run successful without concern for pH? Thanks.

Ph in media other than pure water gets complicated I am learning. Partly because the various concentrations of things keeps changing from plant use and from drying. I think if you don't have a good bit of soil type microorganisms all that matters is the buffering capacity of the medium vs the alkalinity of what you are putting in it vs keeping the media relatively free of salts buildup. What are you putting in it btw? Any patterns to your results? Lol. You've got me curious because I have been pondering trying something like this with small amounts of compost, glacial rock dust and possibly a little of my garden soil for micro life.

[

 

[Kevinhayes]

Use an accurate pH pen to measure the pH of your nutrient solutions. The minimum accuracy I recommend is ±0.05pH. This is how close the sensor and electronics measure the pH compared to its true value. The precision, also called resolution of the instrument is how close the reading on its display comes to the measured value. This is almost always ± the least significant digit of the display. If it's not given, use that value. An instrument with a given accuracy of ±0.1 pH, and display with a single digit following the decimal point with no given precision has a displayed reading ±0.2pH. A reading of 6.0 means the true pH of the solution is between 5.8 and 6.2. An instrument with an accuracy of 0.05pH and a given precision of 0.01pH will have a reading between 5.94 and 6.06 for the same nutrient solution. I've used cheap instruments with great success at accuracies of 0.05pH and precisions of 0.01pH. Currently I'm using a HM Digital pH-200 which has a accuracy of 0.02pH and precision of 0.01pH for a reading of ±0.03pH, or for a nutrient solution with a true pH of 6.0 will display between 5.97pH and 6.03pH.

The key to getting an accurate pH reading is to check the calibration of your instrument before each use. I use Growtek's pH Buffer #7. I recalibrate if the reading is outside the range of pH 6.97-7.03. Every month I re-calibrate the instrument at pH4.0 followed by pH 7.0. This ensures that the pH of my nutrient solutions is as accurate as possible.

Nice great info to bookmark. I'm gonna be using Canna Coco 50L bag.

My question is, do you have to calibrate with the pH 4 and pH 7. Was just about to order the pH 4 solution. Wondering if I should order both?

 

[Old Salt]

The pH 7.0 is usually enough. It's the closest to the values we need. Calibrating at both 4.0 and 7.0 does invrease the accuracy a little.