ph, how important is it.

[pinecone]

Of course it matters, unless you grow outdoors -- isn't rain water's ph 7? I'm really not sure...

A friend has tried to grow cannabis this winter using just tap water, which according to my tests, has a ph of 8.2 or so. After four months of vegetation his plants were still like 15cm tall.

It seems like it depends. A lot of the people that say it matters don't grow in soil. I grow in straight Ocean Forest and it doesn't seem to matter that my water PH is 8.0 (I've seen no benefit to PHing down).

I tried Botanicare Pure Earth which is Coco-based-soiless and had terrible results - in hindsight probably because PH mattered.

Pinecone

 

[guest 77721]

It seems like it depends. A lot of the people that say it matters don't grow in soil. I grow in straight Ocean Forest and it doesn't seem to matter that my water PH is 8.0 (I've seen no benefit to PHing down).

I tried Botanicare Pure Earth which is Coco-based-soiless and had terrible results - in hindsight probably because PH mattered.

Pinecone

This is my point exactly, Pinecone.

There are two methods of growing, soil and hydroponic. In soil growing, the nutrients interact with the soil and the plant can take up the nutrients when they are slightly acidic, pH 6.3 to 6.8.

In hydroponic growing, using rocks, coco coir,clay pebbles, sand, marbles, and perlite, there is no interaction with the nutrients and the medium. The roots must interact with the water and nutrients and need a lower pH to take up the nutrients. In Hydro, the nutrient solution is more acidic, 5-6.

 

[guest 77721]

I agree. I've been helping guys out sorting out basic growing problems and getting their water to match the soil and nutes to start growing def free.

This detailed chart is for the dialed in hydro guys. Personally, my grows are using soilless medium using soil grow methods. Remember I'm the duct tape and rubbermaid guy using hardware and grocery store stuff.

And loving it....

great posts red,
but that pH chart...
Well, it's real pretty and all, but it blows big chunks as far as elemental uptake accuracy goes.

 

[WESTCRAZY1]

great thead!! im all organic so i guess i shouldnt have much to worry about checking the ph

 

[RockyMountainHi]

great thead!! im all organic so i guess i shouldnt have much to worry about checking the ph

ok, now don't take this as an attack,,,,, but,,,,, if your guessing,,,,, uhhhhh,,, ever guess wrong?


having guessed wrong myself (More than once,,) - I'd hate for you guys to go thru that.


SERIOUSLY!.

 

[10k]

Do you have a better one?
Is there anything wrong with the basic information in the chart?

I had another chart that showed all the elements tapering over a larger range but in general the info is still the same as this chart and the big point to the grower is to keep the pH stable at 6.5 for soil and 5.8 for hydro.

great thread Redgreenry

Yes, the second pH chart you posted, IS the better more accurate chart...
It clearly shows why a target start pH of 5.8 is a very poor choice for chem hydro growers...
Just draw a line straight up from the 5.8 and it's obvious why so many hydro growers suffer mag defs, along with several other elements as their pH drifts upwards beyond the preferred hydro working pH of 5.1 to 5.9 (5.2 optimal).

A 5 to 6 is a much healthier range, starting at @ 5.2 for chem hydro grows where the grower is running multi-part chem mineral nute packages such as GH flora series nutes. Once pH drifts upwards beyond 6.4, all sorts of serious defs come into play including p&K 'precipitating' out of the working res hydro solution, but precipitation in solution, poor nute solution mixing/pH'ing and res solution maintenance is another topic altogether, and not something seen on pH charts for that matter.



That other pretty colored snazzy looking square bar chart from page one of this thread just don't cut the mustard imho.

(ps...redgreenry, I edited the image tag in your post to show the chart full sized for clarity)