What is pH?

[1970s Grower]

So what is everyone using for a PH meter?

 

[stokesy]

I'm on my third meter..Blue lab. It's the business, and SO easy to use...first one was a cheapo - useless. Second was expensive, but inconsistent...(cost about $130). a good meter will SAVE you money......

 

[SuKaFr33]

I have a Milwaukee ph600 meter, works pretty good, but i wouldnt say its the best though, but it does the job, i was told to take a cotton swab and dampin it with the ph solution and put it in the cap, that way it stays wet and doesn't dry out..

 

[1970s Grower]

I bought the Hannah 98129 as it was what the Hydro Shop had in stock on the "better" end. No where in the instructions does it say to keep the bulb wet, but I have read elsewhere not to let it dry out.

It is also an EC meter and I am having a hard time rectifying the math conversion to PPM. I can choose .7 or .5 conversion from EC to PPM.. WTF is that about PPM should be parts per million period. There should be no choice of conversion.

Dazed and confused on this one.

 

[stokesy]

I use the Bluelab ec meter - it has the conversions "built in". No complaints about it At ALL! And no, I don't have shares in Blulab....

 

[1970s Grower]

I bought the Hannah 98129 as it was what the Hydro Shop had in stock on the "better" end. No where in the instructions does it say to keep the bulb wet, but I have read elsewhere not to let it dry out.

It is also an EC meter and I am having a hard time rectifying the math conversion to PPM. I can choose .7 or .5 conversion from EC to PPM.. WTF is that about PPM should be parts per million period. There should be no choice of conversion.

Dazed and confused on this one.

]


Went back to the hydro shop and got the solution I need to keep it wet.

 

[RealOrganics]

best way is to measure the runoff when you water with a PH meter. You want to catch and measure the runoff when it first starts dribbling out, so that it's most accurate.

This is very inaccurate. The best way to test soil is with a high quality soil PH tester. If you wish to test soil PH with your pen/water PH tester here is how.

Mix your amended soil in a 2-1 ratio(IE: half cup soil/1-cup water....... 2 TBSP soil/1 TBSP water..... etc) with distilled water, stir well into slurry, let sit for 30 min. This will allow the slurry to stabilize. Then test away.

Testing the runoff of the water will give false readings.

The best way to stabilize PH is to prepare the soil by sweetening it with the ratio of 2TBSP of dolomite lime per gallon of soil. Mix well while dry, add your water and let sit for a few weeks before use. When I do this and then test with the slurry test I get PH 6.2 -6.6 consistently.

It is recommended that you test your soils PH monthly. It is best to take a sample from the bottom 2/3 's of the container. I personally have not done this as I am too worried about damaging the root structure. I prefer to add the lime in generous amounts to ensure stability.

My two cents. Hope this helps someone out.

 

[1970s Grower]

This is very inaccurate. The best way to test soil is with a high quality soil PH tester. If you wish to test soil PH with your pen/water PH tester here is how.

Mix your amended soil in a 2-1 ratio(IE: half cup soil/1-cup water....... 2 TBSP soil/1 TBSP water..... etc) with distilled water, stir well into slurry, let sit for 30 min. This will allow the slurry to stabilize. Then test away.

Testing the runoff of the water will give false readings.

The best way to stabilize PH is to prepare the soil by sweetening it with the ratio of 2TBSP of dolomite lime per gallon of soil. Mix well while dry, add your water and let sit for a few weeks before use. When I do this and then test with the slurry test I get PH 6.2 -6.6 consistently.

I would think that adding distilled water just dilutes the soil PH reading. Also, Distilled water and RO water is seldom neutral at 7.0. Once air gets to the nuetral water it turns acidic from carbon dioxide. I don't think the above method will get you a true soil PH. I think that testing the runoff is as accurate as the slurry method, but I am no chemist.

My theory is that if you start with soil with a known PH... Fox Farm Ocean Forest soil is supposed to be 6.3 - 6.8. ... The just adding the correct PH water/nute combination at 6.3-6.8 should maintain those levels.

 

[stokesy]

1970's grower... In my limited experience, (third grow now), in soil, the ph rises, especially when in flower. This appears to go against what happens "normally". It seems most people experience a drop in ph during bloom. I stand to be corrected, of course..!

I understand the ph alters as the plant draws the required nutrients from the soil. It requires different nutrients at different stages ... and that that's a fact.

Dolomite, in my experience, raised the ph of the soil. It has a natural ph of 10, I believe.

Interesting thread...

 

[Kaiser Sose 3]

OK, So Why would the ph in a top drip bucket change daily? If not twice daily? No nutes added. Straight water for days and it changes from 5.5-7 once to twice daily...

Any suggestions?

 

[Be Irie]

1970's grower... In my limited experience, (third grow now), in soil, the ph rises, especially when in flower. This appears to go against what happens "normally". It seems most people experience a drop in ph during bloom. I stand to be corrected, of course..!

I understand the ph alters as the plant draws the required nutrients from the soil. It requires different nutrients at different stages ... and that that's a fact.

Dolomite, in my experience, raised the ph of the soil. It has a natural ph of 10, I believe.

Interesting thread...

Most peoples PH drops in Bloom because that is usually about the time that the peat has broken down along with the original buffers of the soil... When peat breaks down the soil becomes more acidic, problems are soon to follow... Dolomite will not raise your PH past 7, I have never had it go higher then 6.8, I have used it to bring my PH down also but it usually stops and levels off at 7 ( haven't had to do that in a long time). Dolomite neutralizes the soil, it can raise or lower depending on the PH of your soil.... Also on a side note, if you use to much you will have to much Mag which will lock out Cal and others..

 

[happycarlo]

i say keep it simple! i see tons of highly technical posts from people showing off to nubies. ph is Potential Hydrogen, and measures the soils acidity. most plants including weed need a ph level of 5.8 to 6.8. i recommend 6.2 for unknown strains as a safe bet. using organic ferts with organic nitrogen will not affect ph, but synthetics like ammonium nitrate, or ammonium sulfate will lower ph in a hurry. I would feed organically anyway. Holler at G!

 

[happycarlo]

oh yeah! use rain water too to help keep ph from skyrocketing. city water is usually 7 to 8 oj ph scale.

 

[lookntoimpruv]

The runoff of my soil is 4.5, I have been putting in water or nute solution at 6.5. I am ready to flower, if I do the next few water or feedings at like 7 or 7.5 or more, will that raise it or do I need dolomite?

 

[doublejointed]

this may be a dumb question but here goes...if my plants look and seem healthy(they are growing about 4"-5" a week) should i assume the PH level is ok ?

 

[Kaiser Sose 3]

this may be a dumb question but here goes...if my plants look and seem healthy(they are growing about 4"-5" a week) should i assume the PH level is ok ?

Never assume.

Sounds like good growth but you need to check em. You can get a ph meter from ebay or amazon for very little money.

 

[lookntoimpruv]

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 need help! My runoff water is a ph of 5. I tried adding a higher ph water and feed but it is not leveling. I did not add lime in the beginning because I though that FFOF had been buffered.
I have hard water and use hardwater micro, but once a week it is just ph adjusted hard water. Also the first 5 weeks were just water. Could this be why?
I use FFOF soil and it is week two of flower. I just for the first time noticed some brown spots on some of the fan leaves on just one of the girls. I am afraid more is to follow.
I was told to try to add lime with the proper ratio to some more soil and dress the top few inches.
What to do? I dont know if I gave you enough info but any input would be GREATLY apprieciated!
I

 

[GigaGrew]

One teaspoon of vinegar will lower the ph of a gallon of water by about one full point

One teaspoon of baking soda will raise the ph of one gallon of water by about one full point.

Get the real ph down. It's cheap and although the house items will work they lack the buffers the real stuff has so your PH will not remain stable as long.

Ok i have the real PH Down, but its instructions are dumb, it sas add a bit and test then add a bit more.
Does anyone have a measurement like the above 2 quotes but for ph down?
i have a soil meter but not one for liquids and i need to correct.

 

[Smokemupm8]

Re: Common household items for ph adjustment

Yup!

Vinegar is an acid so will lower the ph.
One teaspoon of vinegar will lower the ph of a gallon of water by about one full point, so 1/2 teaspoon will move the ph of a gallon of water from 7.0 to 6.5.
White distilled vinegar is the cheapest and will work just as well as more expensive types.

Citric acid, aka "lemon salt", is less common as a household item but is another cheap acid to use.
A mere 1/4 teaspoon of citric acid crystals will lower the ph of a gallon of water from 7 to 4.
Herbalcom.com, which sells all sorts of herbs and spices, currently has food grade citric acid for $3.25 per lb. They're the best I've found.


Baking Soda is a base, so will raise the ph.
One teaspoon of baking soda will raise the ph of one gallon of water by about one full point.


Don't put your ph adjuster directly in the media of course. Mix them with your water or nutrient solution. Also, if you're mixing a nutrient solution, keep in mind that fertilizers are generally pretty acidic themselves so will lower the ph of the water you mix them in. The various brands and formulations don't all alter the ph by the same amount though, so there's no simple rule to follow, and of course the more fertilizer you use the more the ph will go down, so you've really got to measure the ph to tell what you're getting. Mix in the fertilizer first to tell where it leaves the ph, then adjust as necessary. If you adjust the ph first then add the fertilizer, you'll end up having to adjust the ph yet again to get it right, taking more time and wasting your ph adjuster in the process.

Great work mate! I was looking for a natural way to lower my tap waters PH and Citric Acid is AWSUM ay!
And youre right about not needing much bro - i put not even a quart teaspoon into7 litres and it went to 4!! So i had to put like one shake into next bucket and perfect-6.0- then even after nutes and Seasol, was 6.2 THANKS FOR GEAT INFO, STIMPY Ren and Stimpy!! Luv dat show.. Cheers again, Smokemup..

 

[Smokemupm8]

Thats true about distilled water, i use it and sometimes it reads 6.4 others over 7.. So yeah, my tap waters fine once sat in a bottle with air holes 24hrs to evap. chlorine, its never higher than 7..
Later guys, thanks, Smokemup