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Why is there a difference in ph between soil and hydro?


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Hey all, thought I come to the guru section and ask this question...

Why do they say to have a different ph level in hydro compared to soil ?

I don't understand the concept here... If marijuana does well in hydro with a base ph of 5.5, then why run your soil grow at a base of 6.2 ?

Reason I'm asking is because I have 3 plants that are doing great in soil with a R/O Ph of 5.8. I am in the process of raising it, but my plants aren't showing any signs of malnutrition or stunting or anything... They seem to like the ph there in...

Hence, raises my question of why am I trying to raise the ph, when their doing fine?

Thanks in advance for any responses....

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Hi,

Fully agree with the Master Tokage.

You ask "Hence, raises my question of why am I trying to raise the ph, when their doing fine?"

In flowering period should raises PH soil to let Potassium and Phosphorus do the job with your plant/buds symbols P;K(famous PK13/14).As the soil pH decreases below about pH 6.0, soil P is increasingly "fixed" into less soluble/available forms by excess soluble aluminum.

In vegetation period u should lower Ph soil to let Nitrogen do the job.

One of the key soil nutrients is nitrogen (N). Plants can take up N in the ammonium (NH4+) or nitrate (N03-) form. At pH's near neutral (pH 7), the microbial conversion of NH4+ to nitrate (nitrification) is rapid, and crops generally take up nitrate. In acid soils (pH < 6), nitrification is slow, and plants with the ability to take up NH4+ may have an advantage.

It's all about nuts :biggrin: link: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex6607

Peace.

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It´s about the uptake of nutes i do belive. The feeding in hydro is a direct thing while soil is slower and release over time. If the Ph in hydro would be to high the uptake would suffer.

But soil can handle it better and slowly.

If the Ph is not at a proper level in a water rez it will lose its ability to absorb some of the essential elements. You do not need to have it at 5.5 and it could go up all the way to 6.5 at the ned of flowering.

Here is a good chart.

post-3817-0-90130200-1357832298.jpg

If anything is unclear let me know and i will try another way to explain.

Thanks Tokage... I've got the same chart up in my grow room :)

But after looking at this chart, and many like it, it would appear that the only thing being hurt with a ph of 5.5 + is the P, the rest are minute... That can be dealt with by foliar feeding, right. Up to a certain point in flowering that is..

I've been growing for many years, and fought high PH many time... That's not a problem, nor is fighting low ph, but still, I'm awful hard headed :) Not really, I just want to understand this...

I also understand that different strains will react to ph differently than others will. Some more tolerable that others...

So it's all about how fast they absorb there nutes. Hydro has faster absorption and soil is slower.. Right ?

So Tokage, would you suggest I get my ph up asap ? :) Or keep going and see what happens in the end, buy continuing to bring it up gradually...

Thanks again friend..

This chart is taken from "Marijuana Horticulture The Indoor-Outdoor Medical Grower"

PH_CHART.jpg

Hi,

Fully agree with the Master Tokage.

You ask "Hence, raises my question of why am I trying to raise the ph, when their doing fine?"

In flowering period should raises PH soil to let Potassium and Phosphorus do the job with your plant/buds symbols P;K(famous PK13/14).As the soil pH decreases below about pH 6.0, soil P is increasingly "fixed" into less soluble/available forms by excess soluble aluminum.

In vegetation period u should lower Ph soil to let Nitrogen do the job.

One of the key soil nutrients is nitrogen (N). Plants can take up N in the ammonium (NH4+) or nitrate (N03-) form. At pH's near neutral (pH 7), the microbial conversion of NH4+ to nitrate (nitrification) is rapid, and crops generally take up nitrate. In acid soils (pH < 6), nitrification is slow, and plants with the ability to take up NH4+ may have an advantage.

It's all about nuts :biggrin: link: http://www1.agric.go...f/all/agdex6607

Peace.

Thanks for the insert Pi2...

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Sorry did not see that you did soil.

If they are in flowering or just started i would go a little bit higher than 5,8.

I've actually got 2 of them running at 5.88 and rising, and one at 6.24. The one at 6.24, I wont adj. any more... As for the other 2, I'll just keep watering at a ph of 6.25 and maybe re-flush again... But their actually doing super...

So thanks guys... I might try hydro some time... But don't you really have to be on top of the ph when doing hydro? I mean if the ph goes south, aren't you constantly adjusting ? IDK if I have the time for that....

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its called cation exchange is why we use different ph values, our foods are called cations, its the ability for the roots to exchane between them to uptake, there is no c.e.c. in hydro..water. so is why its lower for ph than all others. their is nothing for the ellements to obsorb into for the exchange with water vs a soil or other medium.

and dont be moving your ph around. find what yor room, plant and grow style works est at and stick to it. yhour plat is already moving ph always and you also doing so it makin it work harder to chase yours around.

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