A newbie with question about EC and pH

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anolis

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Hi everyone,

My first plant is just flowering. I wanted to try out growing 1 cannabis plant in a simplified way, so I got an all in one feeding powder (Green House brand). Everything was going fine until very suddenly my plant started to display what I believe to be a calcium deficiency during second week of flowering. I bought a calcium supplement, an EC meter and pH drops. I did not get a pH meter as I am growing in soil and read that it is not that neccessary to have it. Now that I have all of that, I wanted to make sure that I got the basics right and ask you guys what you think of these measurments.

I measured pH of my tap water with the pH drops and it seems to be 8.5. I also measured it after adding all the nutrients and calcium powder and it read between 6-6.5. I guess that means pH for feeding the canabis is good? But is pH 8.5 okay on the days when I only water my plant and not feed it? If not, should I also buy and add pH down to get it to the 6-6.5?

I also measured the EC of the tap water which was 0.3. I read somewhere this indicates that my tap water is soft (does not contain alot of Calcium and Magnesium). I also measured EC of my feeding solution and it was 1.7 mS/cm . Is that okay?

In the feeding powder manual it says that you should flush the plant if the runoff is higher than 2.5. But I also got an advice that flushing is not great when growing in soil so it is better to "flush" only by having 50% runoff.

Did I get anything wrong and is there anything else that is crucial to know?

Thank you for your help!
 
HerbalEdu

HerbalEdu

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Gmix said:
Do you have a link to your food
Or know if it’s organic or synthetic & the npk ratio
Click to expand...
he's running green house feeding powder mineral line where nutrient are readily available for the roots.

Mineral Nutrients

shop.greenhousefeeding.com shop.greenhousefeeding.com

so i don't don't remind exaclty wich bag(s) he bought.

they had a grow bag for veg a little while back , that no longer seem to be on the shop but could be eventually replaced with long flowering bag i think.

here's a link to the old feeding chart with the grow bag alongside the others:

 
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phxazcraig

phxazcraig

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Your best bet is to use RO water instead of tap. I'm not surprised by an 8.5 pH reading. I have 8.3 here in Phoenix. When I see my nutrient reservoir drop a bit low, I just toss in a couple of quarts of tap water to quickly raise the pH. You could probably substitute some of the tap water for some of any cal/mag you are adding. I run pH 6.0, but I grow in coco coir, which is quite different in terms of watering schedule. (I feed every 2 hours.)

I don't check the EC off the runoff, but when I used to, I found that it kept wanting to rise during flowering. EC in my runoff became much higher than the input. Never found out why, but now I just water every 2 hours to constantly flush and feed. You can do that in coco, but not in soil.
 
A

anolis

50
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HerbalEdu said:
he's running green house feeding powder mineral line where nutrient are readily available for the roots.

Mineral Nutrients

shop.greenhousefeeding.com shop.greenhousefeeding.com

so i don't don't remind exaclty wich bag(s) he bought.

they had a grow bag for veg a little while back , that no longer seem to be on the shop but could be eventually replaced with long flowering bag i think.

here's a link to the old feeding chart with the grow bag alongside the others:

Click to expand...
Yes I got the short flowering mineral feeding powder and now I just bought the booster PK+ for the flowering stage and calcium from the same company.
 
HerbalEdu

HerbalEdu

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yeah if i remind they advise using their calcium additive because liquid cal mag may precipitate with their nutrients. and most bag got some mg already.

but it seem they revamped their website recently and some infos on the products are less easily accessible. as well as the missing grow bag for veg.
 
A

anolis

50
18
HerbalEdu said:
yeah if i remind they advise using their calcium additive because liquid cal mag may precipitate with their nutrients. and most bag got some mg already.

but it seem they revamped their website recently and some infos on the products are less easily accessible. as well as the missing grow bag for veg.
Click to expand...
Yea you are right. I am generally refering to their PDF guide: https://shop.greenhousefeeding.com/downloads/GHF_M+B_2019_UK-AU.pdf

I guess what I am wondering now is if I stick with my tap water, can I assume it is soft, bordering on medium hard (based on the 0.3 EC reading) and add 50-80% of the calcium that they recommend (page 13 in the PDF), then measure EC and if it is higher than EC total in the example table (eg. more than 1.5 in the flowering week 1) I add less calcium next time and if it is lower, I add more. Am I understanding them correctly?
 
A

anolis

50
18
phxazcraig said:
Your best bet is to use RO water instead of tap. I'm not surprised by an 8.5 pH reading. I have 8.3 here in Phoenix. When I see my nutrient reservoir drop a bit low, I just toss in a couple of quarts of tap water to quickly raise the pH. You could probably substitute some of the tap water for some of any cal/mag you are adding. I run pH 6.0, but I grow in coco coir, which is quite different in terms of watering schedule. (I feed every 2 hours.)

I don't check the EC off the runoff, but when I used to, I found that it kept wanting to rise during flowering. EC in my runoff became much higher than the input. Never found out why, but now I just water every 2 hours to constantly flush and feed. You can do that in coco, but not in soil.
Click to expand...
Would I then use RO both on watering and feeding days? Or does water also need to contain calcium and magnesium on watering days? When I add the supplements to my tap water, the pH seemed to be appropriate, I am only wondering if the pH 8.5 is a problem when watering without adding the supplements?
 
HerbalEdu

HerbalEdu

2,852
263
anolis said:
Yea you are right. I am generally refering to their PDF guide: https://shop.greenhousefeeding.com/downloads/GHF_M+B_2019_UK-AU.pdf

I guess what I am wondering now is if I stick with my tap water, can I assume it is soft, bordering on medium hard (based on the 0.3 EC reading) and add 50-80% of the calcium that they recommend (page 13 in the PDF), then measure EC and if it is higher than EC total in the example table (eg. more than 1.5 in the flowering week 1) I add less calcium next time and if it is lower, I add more. Am I understanding them correctly?
Click to expand...
i think you start with you tap water then you add calcium until you reach the recomended ec value for calcium in the chart then add others product with each additionnal ec step recommended for each products.

for exemple week 3 flowering.

you add calcium to your tap water until ec=0.4 then you add pk and flowering bag to reach total ec.

that may vary with how much calcium and else it represent for this 0.3 ec of you tap water.
 
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Gmix

Gmix

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HerbalEdu said:
he's running green house feeding powder mineral line where nutrient are readily available for the roots.

Mineral Nutrients

shop.greenhousefeeding.com shop.greenhousefeeding.com

so i don't don't remind exaclty wich bag(s) he bought.

they had a grow bag for veg a little while back , that no longer seem to be on the shop but could be eventually replaced with long flowering bag i think.

here's a link to the old feeding chart with the grow bag alongside the others:

Click to expand...
Thanks bud

Strange food really high k & low p
I leave you in herbs hands he’s more knowledgeable than me on this subject

The k lvl is real high though without the pk booster its needs the p however I don’t know if it needs the k boosted seems a bit of overkill on the k tbh

Still am sure herb will put you on the right track & yeah I agree with sticking to your tap water as it’s more beneficial than ro water witch can come with its own problems
 
A

anolis

50
18
HerbalEdu said:
i think you start with you tap water then you add calcium until you reach the recomended ec value for calcium in the chart then add others product with each additionnal ec step recommended for each products.

for exemple week 3 flowering.

you add calcium to your tap water until ec=0.4 then you add pk and flowering bag to reach total ec.

that may vary with how much calcium and else it represent for this 0.3 ec of you tap water.
Click to expand...
I would do it this way if I used RO water, but since I need to add less calcium than what they recommend due to using tap water, it seems more logical to me to start with the nutrients and then slowly add the calcium until I reach desired total EC. Or am I missing something?
 
HerbalEdu

HerbalEdu

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anolis said:
I would do it this way if I used RO water, but since I need to add less calcium than what they recommend due to using tap water, it seems more logical to me to start with the nutrients and then slowly add the calcium until I reach desired total EC. Or am I missing something?
Click to expand...

GHF soil shortfloweringchart


your tap water ec is 0.3, wich could a mix of few nutrient including calcium, but can't really say wich amount.

so if we consider week 3 of flowering, your total ec should be 1.6

you start with 0,3 wich for part is calcium, you need 0,4 calcium so i would try complementing the tap water with calcium powder until ec reach 0.4 or may be 0.5 depending how much calcium is effectively in your tap water.

then i will add short flowering until ec rise by 1.0 and reach 1.4 or 1.5

finally adding the booster pk+ until ec rise by 0.2 and reach the recommended 1.6 value or 1.7 if you try with a little more calcium

but you may do the addition of products in an other order as well, i m not seeing them recommanding mixing their nuts in any perticular order. That could happen with some liquid synthetic nuts.
 
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A

anolis

50
18
HerbalEdu said:
View attachment 2417353

your tap water ec is 0.3, wich could a mix of few nutrient including calcium, but can't really say wich amount.

so if we consider week 3 of flowering, your total ec should be 1.6

you start with 0,3 wich for part is calcium, you need 0,4 calcium so i would try complementing the tap water with calcium powder until ec reach 0.4 or may be 0.5 depending how much calcium is effectively in your tap water.

then i will add short flowering until ec rise by 1.0 and reach 1.4 or 1.5

finally adding the booster pk+ until ec rise by 0.2 and reach the recommended 1.6 value or 1.7 if you try with a little more calcium

but you may do the addition of products in an other order as well, i m not seeing them recommanding mixing their nuts in any perticular order. That could happen with some liquid synthetic nuts.
Click to expand...
Perfect, thanks! Do you think using tap water as is is fine on watering days? They recommend switching between watering and feeding days. But then pH is around 8.5.
 
HerbalEdu

HerbalEdu

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anolis said:
Do you agree with Gmix that this nutrients powder might not be good due to too much K?
Click to expand...
if it was me i think i would have opted for the long flowering formula 18-12-18 over the hybrid 15-7-22 or short flowering 16-6-26 formula
 
A

anolis

50
18
HerbalEdu said:
if it was me i think i would have opted for the long flowering formula 18-12-18 over the hybrid 15-7-22 or short flowering 16-6-26 formula
Click to expand...
Ah okay. I got the short flowering because I am growing an auto (gorilla cookies) which was said to take only 9-10 weeks from germination to harvest.
 
HerbalEdu

HerbalEdu

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anolis said:
Ah okay. I got the short flowering because I am growing an auto (gorilla cookies) which was said to take only 9-10 weeks from germination to harvest.
Click to expand...
just in general plant still need lot of N along flowering and most other nutrient brand use rather equal ratio of P and K, then the PK booster will bring additionnal PK need in equal ratio as well.

so you can adjust the amount of long flowering related to pk booster to bring a little less or little more N along flowering eventually.

the long flowering NPK ratio is close to all purpose nutrient equal ratio, and you can grow cannabis with all purpose nutrient from start to finish and get decent result.

you can even use it in veg in replacement of their grow bag and the plant won't bother that much.
 
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Gmix

Gmix

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HerbalEdu said:
not sure about his plant issue, but it's just i have been looking into this nutrient brand.
Click to expand...
As you know I’m a organic grower
Your more all round & know more about his food I had a glance but I didn’t see anything saying organic on it.
If it was an organic grow I’d be all over it but it’s not is it ? Is his food actually organic

There’s more than a calcium deficiency going on
I remember your pic I think & I said back then it wasn’t a calcium issue & when really what I should have said it it’s more than just a calcium deficiency. You’ve got twisted leaves & the leaves don’t look healthy

If your gonna rule out ph & am not so sure about that then there really only temperature or lights being to close however they don’t look like the lights to close. That & off course your watering habits might explain the color of the leaves however it wouldn’t explain the twisted leaves

Have you another pic of the whole plant
 
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