PH fluctuations

Chippers

New Member
Hi everyone,
I'm not sure if this is a common problem with you guys or if I'm doing something wrong, but whenever I get the water right for my girls whenever I test it again before the next watering its changed and normally dropped. How can I stop this so it stays the right PH in my watering can? Any advice appreciated thanks, I'm getting sick of having to dump the water cause I can no longer use it. I'm growing in coco coir and try to keep it about 5.8-6.0.
 
It's not clear exactly where this pH-changing water is. You're mixing up a big batch of nutes and the pH is changing when it sits? That's not unusual. In water without a lot of mineral content to buffer it, the pH of the solution can change just by shaking it up. (For a fun science experiment, measure the pH of some water as you blow air into it with a straw, which adds carbonic acid from the CO2 in your breath.)

If the water you're using does have a lot of mineral content in it (i.e. it's "hard" water), there may be some change in its pH over time as the carbonates etc interact with the fertilizer. (Think of the pH of a cup of vinegar rising as a piece of chalk slowly dissolves in it, for example).

The pH of coco coir has an ideal range of 5.5 to 6.5 according to my grow guru. There's really not too much point in chasing 0.1 pH changes. Bear in mind that commercial hydroponic solutions are formulated to make nutrients available across a range of pHs.

In any case, you shouldn't need to dump the juice just because it's not at precisely x.x pH. Your plant really doesn't care.
 
Right ok, I'm not using nutes as they are just babies sometimes it drops to 5.0 would this be too low for my plants?
 
You show your location as being in Durham. Their water report shows a pH in the low 7s, which should be fine.

https://durhamnc.gov/ArchiveCenter/ViewFile/Item/2889

How are you measuring pH? If you are using a pH pen, have you carefully calibrated it? (If you're using one of those awful garden center combo pH thangs, throw it away now.)

Since you seem interested in the subject, you should read up on it. It's a little complicated.
 
I'm using a yellow pen thingy I got of ebay that you just turn on, isn't 7.0 a bit high for growing in coco coir?
 
I'm using a pen I got of ebay that you just turn on, isn't 7.0 a bit high for growing in coco coir?

Again, a pH pen is an extremely delicate instrument that works by measuring an ionic gradient across an extremely thin glass bulb. It has to be carefully maintained and carefully calibrated to give useful information. You don't just turn it on and off.

If you aren't going to calibrate it in pH 7.0 calibration fluid and carefully maintain it, you are better off using pet store aquarium pH measuring drops. Otherwise you are just getting "magic numbers" from the pen that can be WAY off. The pH scale is logarithmic, so a small number change is a BIG difference (e.g. pH 6 has ten times more ions than pH 7, and pH 5 has 100 times more).

The ideal pH for coco is about 5.5 to 6.5.
 
It's not clear exactly where this pH-changing water is. You're mixing up a big batch of nutes and the pH is changing when it sits? That's not unusual. In water without a lot of mineral content to buffer it, the pH of the solution can change just by shaking it up.

Or by aerating it? Been a while since I had a working pH meter (I know, I know...), but I was thinking that can change the reading. But the period in my life when I came up with that thought... was kind of foggy, so I could easily be misremembering.

Does the presence/absence of chlorine affect pH? If so, might this be a sign that the water wasn't completely dechlorinated the first time the pH was checked?

IDK if this one is true or just an Internet Rumor, lol, but I'm pretty sure that I once read certain household things, if used as pH adjusters, may be somewhat temporary in nature. Do you know if this is true? I think what I read might have been in reference to... baking soda?

Chippers, what are you using to adjust your pH? Do you keep your water aerated in between uses, or aerate it for a period of time before checking its pH (each time)?

If the water you're using does have a lot of mineral content in it (i.e. it's "hard" water), there may be some change in its pH over time as the carbonates etc interact with the fertilizer. (Think of the pH of a cup of vinegar rising as a piece of chalk slowly dissolves in it, for example).

Since you mentioned vinegar... Might the dissolved solids in the water be interacting with the pH adjusters in the same manner? Either commercial adjusters or ones sourced from the kitchen?

Speaking of commercial adjusters, I was told some years ago not to use ones intended for swimming pool use. Again, IDK. I always just used something like General Hydroponics' pH down, which is.... phosphoric acid? Seems like plants can use phosphorous. At the time, in the reservoirs... If memory serves, I could add a little of the "Bloom" component and the pH would settle back down (if it had risen, due to nutrient consumption).

Having trouble thinking clearly today, for some reason. I can't even spell, lol.

The pH of coco coir has an ideal range of 5.5 to 6.5 according to my grow guru. There's really not too much point in chasing 0.1 pH changes. Bear in mind that commercial hydroponic solutions are formulated to make nutrients available across a range of pHs.

Since the peak availability for different elements seems to be at different pH "points," a little drift might be a good thing? But that's in a nutrient reservoir, not in the watering can.

(If you're using one of those awful garden center combo pH thangs, throw it away now.)

I've thought about putting that in my .SIG a time or two, lol. I'm surprised anyone ever buys those things.
 
I'm using a yellow pen thingy

Is it a Milwaukee pH600? Those are yellow. Cheap as chips. Reasonably accurate, in my experience - used one when I only had $21 to spend, then kept it as a spare until I ruined it by allowing its probe to dry out. Oh, BtW, don't do that, lol. And DON'T store them in distilled water, either, IMHO.

If you aren't going to calibrate it in pH 7.0 calibration fluid and carefully maintain it, you are better off using pet store aquarium pH measuring drops.

Assuming the probe is still good (not dry, contents not leached out by storing in distilled water) and that it's "only" out of calibration... Would it still be capable of showing pH rising or falling?

I need to save up for a replacement probe for mine. I actually have no clue what the pH of my nutrient mix (or water, for that matter) is. And I should know better. Distressing....
 
ugg, the dreaded PH again. Bro, that Pen sucks. Mine was right, probably never, lol.. AND i calibrated it from the start, AND i checked the PH of Stable RO water that i knew was 6.5 PH. Still sucked each and every time. That yellow one from Eby.

I switched over to PH perfect Advanced Nutrients, and WOOOOOOOOOOOOh, soooo glad i did. Dont miss the PH problems, that for sure man.

Im not here pushin products, but you wont have PH issues no more if you went the route i did. Im coco too.

6 days since the change from FoxFarm to AN, Just flipped to 12/12 last night. 28 days from seed.
flower1-2.png
 
I switched over to PH perfect Advanced Nutrients, and WOOOOOOOOOOOOh, soooo glad i did. Dont miss the PH problems, that for sure man.

Cool. I've still got half-full bottles of Flora Series nutes, but I think I'm going to use those to fertilize the tomatoes and flowers (works great) and for drian-to-waist coco (for which pH isn't a problem because you refresh the nutes daily) and try the pH Perfect line for the next hydro grow.
 
Looks lush dude, I think I'm going to have to sort something out. I've just checked out to calibrate the pen and it says I need deionized water. As far as nutes go I've got canna a and b or I'm thinking about Iguana juice as I've heard good things about it. As mine are just babies at the minute I'm not using nutes yet but will check out advanced as well.
 
Is the deionized water to make up the powdered pH calibration solution that came with the pen? If so, may I suggest that you just toss that stuff and order a bottle of GH pH 7.0 calibration solution from Amazon instead? You want calibration solutions to be extremely accurate, and you just can't get that level of accuracy with kitchen measuring cups.

As for nutes, I'm going to suggest just using the Canna A&B and see how that works without a lot of extra crap, er, products. My standard soapbox harangue is that all cannabis really needs is NPK+micronutrients, and you get all those in any properly mixed commercial fertilizer. The marketers really want you to spend a lot of extra $$$ on ten more bottle of rocket juice, but IMHO that's really not needed.

My .02. Happy growing.
 
Well to be honest I don't really want to spend too much money on my grow gear and I got the Canna A and B along with my kit along with tent etc. I've wanted to grow for years and I'm fed up with dealing with some people that are unsavoury to get what nature blessed us with...so here I am lol
 
Chippers, either spend the $65 or whatever for a higher end PH pen, or go PH Perfect. The PH is by far, the most important part of the grow. With that incheck, CONSISTENTLY, its one less thing you have to worry about. PH problems took the fun outta the whole process, not to mention the wasted time, because I actually was doing DWC before Coco, and went thru a sht load of water, advil, and meds dealing with this sht.lol.. Trust me, The $31 for the AN Perfect Trio is dam well worth it.

Now, they look decent under my 1125 watts.
 
Yeah I am I'm going with advanced nutes ph perfect as I don't want the hassle and they aren't that expensive...thanks for the advice. I'm looking at the sensi one, is the perfect trio the one with the grow, micro and bloom? The one with the gorilla on the bottle?
 
Yes Chippers, with the Gorilla, and it also says PH perfect on the bottle, grow, micro, and bloom. ALso, You NEED to get Cal-mag, so dont forget that. Use RO water, and first thing you need to do, is get your PPMs up ato 110-120 PPM BEFORE you add your nutes. Which is 13ML per gallon of water, for me. Depends on your option of Cal-Mag u go with Id assume.

Good luck bro
 
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