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What is pH?

John C

Product Reviewer - Formerly Known As KingJohnC - M
Yea, bringing this back. New hydro grower here and just got a waterfarm. I've had huge PH swings during germination from just plain water. Drove me nuts and GH, of course, said my water quality is causing the problem. I read a grow journal here and the guy had a waterfarm and had the same problems I had. Long story short...I googled "PH issues with hydroton" and was shocked at all problems guys have with PH rising from hydroton. Waterfarms use a lot of hydroton in a 2-gallon res hence the dramatic increases in PH. An expert claimed that rinsing hydroton in a 2:1 water and vinegar solution helped stabilize it. I simply rinsed it in water until there was no residue left; a newb mistake. All that said I'm 2-weeks into veg and my PH increases about 1-point in about 12-hrs. My TDS is about 450 PPM. I'm adding 1-1/2 mil of PH down twice per day to keep my PH around 5.8. Is adding this much acid to my res going to hurt my girl? She looks fine and growth is consistent.
I would first double check your pH meters calibration to maintain accuracy and continue to readjust the pH of your Waterfarm to pH 5.8.
 

Slowpuffer

Well-Known Member
It can be very difficult near impossible to grow a healthy plant without proper understanding of pH and the tools to monitor and adjust the pH.

A must is a good digital pH meter.

I feel like this should be a sticky. A lot of beginner growers including myself treated pH as an after thought. These days I spend close to an hour carefully testing and adjusting my pH each feeding/watering and my results have improved drastically.

IMO pH issues are the root of almost every mystery problem.

Great thread.
I bought a hanna, which was recommended by another member and it lasted 4 months. I then bought a 15$ online meter from china and the only difference is the cheap meter has to be calibrated more often. Other than that, it's excellent !!
 

tucker99

Active Member
Calibration is key!
You bet! But, I sprung for the storage solution and found that I didn't need to calibrate it as much. I think a lot of guys let their PH meter dry out. Keeping it wet is important.
 

John C

Product Reviewer - Formerly Known As KingJohnC - M
Welcome to 420 Magazine Greenethumb42! The pH that you should be adjusting your nutrient mixtures strength to is dependent on the type of medium you use to grow your cannabis plants in. You want 6.5 pH for soil and 5.8 pH for peat moss, coco coir and hydroponics. I believe that you may have a nutrient buildup in your grow medium and should flush your plants grow medium with at least twice as much volume of pH adjusted water as pot size or until your runoff liquids pH is the same as the waters pH your are flushing with.
 

GDfan

New Member
ok heres a question for you guys who know more than I do first of all I am a small 3-4 plant soil grower using leds fox farm soil and technaflora nutes well I was given a brand dandy new blue lab growers tool box with both a ppm pen and a ph pen my question can I use this pen which is for hydro to measure my run of water to get my ph levels I know they sell a pen just for soil but cash is short
 

DRM Ranch

New Member
You can, just make sure to keep the pen in storage solution or pH 4 calibration fluid, and rinse it off after each and every use.

Exactly how useful something is or will be is more a function of how you use the tool than anything else.

While it is always nice to have the proper tool for a job, that always isn't going to be possible.

Just be smart about how you interpret the readings you take, and you should be fine.

Google how to store the pH pen and get a good idea of why it is important to keep it stored properly, this will pay off in the long run.

Keep a log of your readings, even if they don't help out greatly right now, a history of readings can identify issues down the road.
 

GDfan

New Member
thanks for the tips this indoor stuff is all new and there isa big learning curve lol so check the run off and go up or down as needed
 

PurpleGunRack

Well-Known Member
In my job I often test for pH, EC and dissolved Oxygen when taking water samples from geotechnical/environmental boreholes,
and some of the things the companies that sell pH measuring equipment advise you to do are just not that true.


Storage solution:

The storage solution is basically a salt water solution and dirty/brackish water or buffer solution 4,0 works just as well, though the storage solution is cheaper than the buffer solution.
It was just made to make a standard in the industry and to stop customers calling and asking what kind of saline solution to store their meters in.


Demineralised (distilled) water:

Even though some companies tell you to rinse in deminaralised(distilled) water, this is not a good idea as it will wear out the probe faster
(the ions in the Hydrogen diafragma will want to escape into the un-ionized water and thus wearing out the diafragma faster and shorten the probe life)


Calibration:


Use the calibration buffer to rinse the probe with before calibrating with a new cap of it(stir the probe around well and let the value settle).

Make sure the calibration buffer liquid is not too old.

Never re-use calibration buffer liquid.

Use seperate caps for the different buffer solutions.

Calibrate every 7-14 days to keep the meter accurate.

The buffer solution 10,0 is not necessary unless you need to measure high alkaline levels often (which you shouldn't need for growing purposes) and it has about half the shelf-life of the 7,0 and 4,0 buffers.


Equipment:

Cheap meters can work just as fine as expensive meters, and either way the probe needs to be replaced every 1-4 years depending on usage and storage/cleaning discipline.

You might be able to save a lot of money looking for pH measuring equiment outside growshops.


:Namaste:
 

PurpleGunRack

Well-Known Member
ok heres a question for you guys who know more than I do first of all I am a small 3-4 plant soil grower using leds fox farm soil and technaflora nutes well I was given a brand dandy new blue lab growers tool box with both a ppm pen and a ph pen my question can I use this pen which is for hydro to measure my run of water to get my ph levels I know they sell a pen just for soil but cash is short
Sift it the run-off through a clean cloth into a clean bowl and use the pen in it.
 

PurpleGunRack

Well-Known Member
I just bought the HM digital PH hydrotester for $50. from the grow shop and now I must learn how to use it. I was told only hydroponics growers need to PH. Im thinking ALL needs to be PH'd????
Should be pretty straigh forward, if you read the manual to your pen and my post a couple of posts above you're well on your way.
You might need to leave the pen in for a couple of minutes for the value to stabilise.

Yes basically all growing is optimised by having a correct pH, soil is more forgiving to small changes in pH and reacts slowly, where hydro is not so forgiving and reacts almost instantly to changes.
 

tucker99

Active Member
Mentioned before, calibration is the key. Invest in PH 4 & 7 calibration fluid and the storage solution. Should be able to get it all for under $15 and it should last for years. Yea, I did all that but forgot to get spare batteries. My meter takes about a minute to settle down before the reading stops jumping all over the place. Not sure what's up with that and replacing the batteries. They're a year old but I use my meter frequently.
 

Wallykazam

New Member
So why is a pen you need to clean and calibrate better than a strip or a tubed soil test......the whole calibration thing seems like a real pain in the ass.....what if you get it wrong?
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
So why is a pen you need to clean and calibrate better than a strip or a tubed soil test......the whole calibration thing seems like a real pain in the ass.....what if you get it wrong?

Pretty difficult to get it wrong. Generally it involves putting the ph probe in the appropriate calibration solution and pressing the calibrate button.
Pens and meters are more accurate than the strips and drops. When they're working.
 
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