The PH battle

I am almost nearing the end of my first grow, last night I couldnâ??t sleep thinking do I want to do this again? Well NO, but no one should expect perfection so Ill give it another try.

. . I have battled low PH from day 1. If I set it at 6.5, in 24 hours its under 6.0. Double check by using the meter and the drops it plunges. So I used the entire bottle of PH UP in just over 9 weeks and I opted 3 nights ago to use Baking Soda to raise the PH. Using warm water and baking soda, got a PH at 6.54 and didnâ??t touch it as I predicted it would be 6.0 next time I check.

Yesterday I carry out the same routine as usual, but for the first time ever my PH has gone up to nearly 7. Yeah I had to triple check to make sure, but for the first time ever my PH went up?

I think the baking soda is the obvious cause, and I think as water evaporated it became stronger.



One more question, I got neem oil to tame some powdery mildew itâ??s the oil extract but how often do I spray the plants with it?

im also a soldier on the front line in the war against unstable pH levels. Dont stop growing tho, imo you can still get a good yeild without trying to hard. I saw a thread where someone grew 1 plant in crap soil with no nutes and no pH bal and he got almost 1 oz from just that plant which is good considering he used 1 cfl and the plant was no bigger than 10-12" tall. Just keen trying :)

Start with a composted humus based soil rather than peat based. The pH is much more stable over time, as the humic acids act as a buffer.
I have a question; how long did you let any given plant remain in the same pot without re-potting?

I think luv is growing hydro......Luv....you've hit the reason the many hydro growers switch to RO and/or distilled water. It REALLY HELPS keep your ph under control and you also know exactly what and how much minerals etc your plants are getting in your hydro conditions. But the ph thing alone is worth it imo. ;)

luvfriday: A whole bottle of ph up in a couple of weeks? I've got the opposite problem. My well water comes out at around 8.1, but I use GH's ph down. (phosphoric acid) I got a gallon a couple of years ago, and still have 1/2 gallon left, and use it for my houseplants, too.
When was the last time you calibrated or checked the accuracy of your meter?

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Originally Posted by darbolah

imo you can still get a good yeild without trying to hard. I saw a thread where someone grew 1 plant in crap soil with no nutes and no pH bal and he got almost 1 oz from just that plant which is good considering he used 1 cfl and the plant was no bigger than 10-12" tall. Just keen trying :)

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Any chance of getting that link from ya? I'd love to find out how to do a half-assed job, with inadequate lighting and no nutes, yet still have a smokable result. How was your next grow?

1/2 liter of PH down lasts about as long as a gal. of PH up for me. I also notice that it takes much more PH up to raise ph than it does PH down to lower it. The instructions state that 1 teaspoon of PH down or PH up will move your PH the same amount. I don't find that to be true.

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Originally Posted by grey1223

1/2 liter of PH down lasts about as long as a gal. of PH up for me. I also notice that it takes much more PH up to raise ph than it does PH down to lower it. .

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Yeah and this is because pH up is (I believe) Potassium hydroxide, KOH, and pH down is Phosphoric acid, H3PO4- a tri-protic acid, and VERY strong.
The active components in each are the -OH group and the -H respectively.

whats the verdict on baking soda to raise Ph? Does anybody know if it causes any lockout after awhile.

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Originally Posted by Mr. Brown

whats the verdict on baking soda to raise Ph? Does anybody know if it causes any lockout after awhile.

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Yup. Sodium bicarbonate.
It's a weak base, not a strong base, and does not include the desirable -OH group, so you have to use a lot to get the same effect, plus it has a buffering range of its own. The active group in baking soda is a carbonate ion, CO3, the same as in lime, but lime contains Calcium as the positive ion, rather than Sodium, which at more than trace levels is detrimental to plant health.
You're safer with lime, but FAR better off with KOH.

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Originally Posted by stinkyattic

Yup. Sodium bicarbonate.
It's a weak base, not a strong base, and does not include the desirable -OH group, so you have to use a lot to get the same effect, plus it has a buffering range of its own. The active group in baking soda is a carbonate ion, CO3, the same as in lime, but lime contains Calcium as the positive ion, rather than Sodium, which at more than trace levels is detrimental to plant health.
You're safer with lime, but FAR better off with KOH.

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so PHHHHHHHHHHHHHH! :D