PH pen .... should i trust it ??

Hi everyone ,

Im 4 weeks into my first indoor grow. Everything gone great so far. I noticed that my Ph pen (4 weeks old) , the yellow one for about 30€ gave a different reading for the tap water. I got some callibration liquid n it was off so i reset it.
2 things here : firstly im worried because i re-potted 3 n used about 3 litres of mixed nutes , so i assume the stressfull re-pot for the girls wont be helped by not being able to take the nutes.
The second worry is , tomorrow i turn onto flowering n have a whole stack of new nutes i need to give em, n although i have re-callibrated the pen i dont know if i should trust it ?
Is the obvious answer to go out n spend loads of money on a better Ph tester , if so which one ?

Thanks in advance for any words of wisdom

But a better one

Turbo head said:

But a better one

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any sugestions ?

a few wtf here. why are u so worried about ph if you are growing in soil and aren't those yellow ebay ones like $10 ?

the $10 ebay ones are fine just get some calibration and try not to get it wet. Also, if you just repot then allow some time for recovery before throwing into flower would be my suggestion.

I use the cheap ones, just calibrate it. If you have fertilizer that ph's it's self, just stick it in the fertilizer and see if it says something around 6.3-.6.6, usually mine is right a at 6.5. The cheap $10 work fine for me when PHing my water.

Assuming you did your repot flawlessly then just roll with it. As Critical said, you should give it some time after transplant but since you are the one who did the transplant you know better then us how that went. Flawlessly = stay with the plan. If they fought you coming out of the old pots, you bess wait a few days before switching the lights. Fuck that 3 liters....for all you know it was right on pH. Too late to do much about that now except send a pHed water chaser through the bucket.

I have used the GH drops for pH for years - never had a problem. No calibration, no storage solution, no 4.0 an 7.0 calibration solutions.

LetsGetCritical said:

a few wtf here. why are u so worried about ph if you are growing in soil and aren't those yellow ebay ones like $10 ?

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orbo said:

Assuming you did your repot flawlessly then just roll with it. As Critical said, you should give it some time after transplant but since you are the one who did the transplant you know better then us how that went. Flawlessly = stay with the plan. If they fought you coming out of the old pots, you bess wait a few days before switching the lights. Fuck that 3 liters....for all you know it was right on pH. Too late to do much about that now except send a pHed water chaser through the bucket.

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yer orbo , cheers for that , i guess i may be panicing about nothing. A Ph,d water chaser is a top idea.

MickFoster said:

I have used the GH drops for pH for years - never had a problem. No calibration, no storage solution, no 4.0 an 7.0 calibration solutions.

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Been doing the same for 25 yrs...always bang on.

I got one of them yellow ones the other day, it says 6.0 and the GH drops say closer to 5, its been calibrated and rest in 7.0 fluid, gets rinsed in 7.0 agter testing then into the 7.0 fluid always says 7.0 when i turn it on before testing but drops still say around 5....now, which one would you trust?

Drops are a good way to double check if you pen is dead. The cheaper the pen, the faster they die

Could the drops or testing vial be contaminated causing wrong reading? Like i said every time i stick the ph pen into the 7.0 it reads 7.0 not even .1 either way like they say it could be off its a +/- .1 accuracy claim on the package

koda7225 said:

I got one of them yellow ones the other day, it says 6.0 and the GH drops say closer to 5, its been calibrated and rest in 7.0 fluid, gets rinsed in 7.0 agter testing then into the 7.0 fluid always says 7.0 when i turn it on before testing but drops still say around 5....now, which one would you trust?

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HeyKoda , yer i think after a couple of days of full stress , im gonna go down my grow shop n probably ditch the yellow pen for a better quality one. I spoke to a shop in UK yesterday that suggested an "essentials" ph tester n said it was totally bullet proof. ive read a bit about em n it seems like they are well good. Its defo true that the cheaper they are the quicker they die.

troyf said:

HeyKoda , yer i think after a couple of days of full stress , im gonna go down my grow shop n probably ditch the yellow pen for a better quality one. I spoke to a shop in UK yesterday that suggested an "essentials" ph tester n said it was totally bullet proof. ive read a bit about em n it seems like they are well good. Its defo true that the cheaper they are the quicker they die.

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Ive heard alot of good about the blue lab meters to but ive not got that much money right now....im gonna trust the pen for a bit and watch for changes in the plants and see what they say

koda7225 said:

I got one of them yellow ones the other day, it says 6.0 and the GH drops say closer to 5, its been calibrated and rest in 7.0 fluid, gets rinsed in 7.0 agter testing then into the 7.0 fluid always says 7.0 when i turn it on before testing but drops still say around 5....now, which one would you trust?

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That can depend on if the drops are expired or possibly contaminated too.

LetsGetCritical said:

a few wtf here. why are u so worried about ph if you are growing in soil and aren't those yellow ebay ones like $10 ?

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This guy has it right. pH testing in soil whether going in or running off is a fool's errand. Simple paper test strips - cheap and available at any swimming pool supply or hardware store work very well if kept dry and replaced after a year.

Thats kinda what i mean....how do you know which is wrong if both say 7 with the 7 solution