Deficiency?

[Bluey]

First things first.

You need to correct your pH inputs to suit your medium.

Your current pH inputs are great for growing in coco which is typically 0.4 lower than for soil. But you are in soil.

So start feeding with a higher pH. Next feed input at 7 and then bring it back down a little to average around 6.65.

Peat is not a great admixture because it has very low pH. Too low for cannabis

Your Mg deficiency is caused by low pH.

[Gingerbeard]

Camboja You said, "Yes, I adjust it, and I’m giving the water at 6.2. I use a mix that we have here in Brazil..." when asked about pH.
Does that mean you are adjusting your nutrient solution to 6.2 pH or does that mean you are giving nutrients to 6.2 pH water?

To the forum. From what I think is the website 'Carolina Soil' is 70% Sphagno Peat + 30% Vermiculite + Limestone. It calls itself a 'soil substrate.' Is that basically what coco is? Something inert for roots to grow in? And do I remember something about growing in peat needing special pH considerations?

[Bluey]

Peat is very low in pH. Not really suited to cannabis. It appears from what you have noted they have added lime to bring the pH back up. Not inert.

Coco is the husk of the coconut shell. Typically small to medium size chips for cannabis but they also do fibres and dust I think. It can be used on its own with liquid nutes. pH is 6.0 typically.. Its not quite inert on a first grow as it releases P or K from memory around week 3 or 4 and hogs/steals/ binds with magnesium. But its still an exceptional grow medium.

Mag deficiency is typically low pH issues. No coco in that medium so I'd be raising the pH quite a bit. I really know nothing about that soil mix though.

[Camboja]

Yes brother, iam using this Carolina Soil' is 70% Sphagno Peat + 30% Vermiculite + Limestone.
Yes, I mix the fertilizers and then adjust the pH. I was watering with a pH of 6.2.
Thanks for the tips, so I'll start watering and try to leave the default watering at 6.6?

[Rwise]

With all that peat you will be fighting PH issues, would be great for growing blueberries. The limestone will help a bit but probably get used up fast.

[Gingerbeard]

'Carolina Soil' is a misnomer. It is no more soil than a coco/perlite/limestone blend is soil. That might be an issue in people recommending raising your pH.
In my previous post, I asked about the inertness of Carolina Soil vs coco/perlite, which is what I use. Coco/perlite nutrient solution pH usually runs 5.8. Up until now, it looks like you have had a right-fine grow so your pH has been pretty good. I am questioning raising your pH at this point because growing in an inert medium like coco has recommendations to lower pH during flowering.
I also noticed the date on one of your bottles. Is that an expiration date from 2022 or when you bought it?

[Gingerbeard]

Absolutely. Multiple sources.

[Bluey]

So here's what I want to know @Gingerbeard

Where did you find the information that you should lower the pH in flower relative to veg?

This in my mind is not the correct approach so I'm keen to find this source as I want to know why they are saying that.

[Camboja]

Yes, what you're saying about pH makes a lot of sense! I think that in my case the plants are lacking food and I should aim for a pH of 6.2, right?

[Gator]

Why not, you can Google anything, just beware of what you read

[Camboja]

Thank you very much for the answers, I will try to raise my pH to 6.6! No, it is the manufacturing date of the nutrients 2022. I really confess that I am a little afraid of raising the pH! But I will trust you.

carolina soil composition:
Peat 50% and Perlite 50%

[Gingerbeard]

Please forgive me and Bluey for hijacking your thread. It's how we learn.
I hope you'll keep posting on how things turn out.

[Camboja]

No problem my brother, I'll post pictures of how the plants looked in 7 days? So I can see the results, right?

[Gingerbeard]

I like 7-day updates unless something happens. See you then.

[Gingerbeard]

Bluey I never made a recommendation about pH, either way. I questioned raising pH when I had read otherwise. I do not recommend on pH or nutrient issues, only give experience and ask questions. It would be inappropriate for me to recommend on such things because I have not had to overcome pH or nutrient issues. My recent advice has pretty much been limited to, 'Don't marry your first cousin.' and 'Don't top autos.'
CoCo Hydroponics - GreenCoast Hydroponics Knowledge Center

[Bluey]

I have gone to some length in the past to take accurate runoff pH measurements of perfectly healthy plants and found readings all over the place, into the low 4's and if I "corrected" the inputs to fix the run off I would have fucked my healthy plants.

Runoff is never a measure of anything in regards to pH. There is an enormous exchange of ions at the plants root zone which completely fucks with the pH outputs so it is wise to not even measure it.

As to pH at different stages I start at 6, once established, drop to 5.8 and up to 6.2 and slowly raise the lower reading and let the upper climb to 6.3ish. But make sure I hit 6.1 regularly for K & manganese uptake in flower. The charts for coco grows vary a bit re nute uptake but they offer a pretty good guide.

I should probably vary my pH a bit wider to the lower side especially for my sativas as they always run into strife in coco in flower and I don't know what the deficiency is, but if I back my lights off a little it doesn't happen so bad.

In soil pH inputs 6.2 to 6.5 in veg and 6.5 to 6.8 in flower as a rule.

[Gingerbeard]

Bluey your last sentence is what piqued my interest in this thread. Is Carolina Soil, soil, or more inert, like coco? Should CS follow traditional, premixed/bagged/corporate soil pH rec's or lean toward an inert medium pH? If someone told me to shoot for 6.8 in coco, I'd block them. But sphagnum is not coco.

[Bluey]

I think the most controlled grow is pure hydro like DWC or aeroponics, no medium to worry about and a starting pH of 5.8 and let it climb. What could go wrong? Lol

The OP probably has it sorted already. I'd give it 7 then 6.8 for a few feeds then see where im at.