PH chart comparing soil PH to Soilless/hydro

M

meduser180056

Active member

• Aug 17, 2006

• #1

Check out this chart I came across over at another site.

What do all you Icer's think?

According to this chart optimum Ph for soilless is around 5.2-5.5. I always thought it was higher.

Cool chart. Crazy the difference between soil PH and soilless.

 

sproutco

Active member

Veteran

• Aug 17, 2006

• #2

That chart/table is bs. Best ph range for soilless mix is 5.6 to 6.2 Below 5.6, micronutrients get too available especially manganese. They can become toxic. Hydro ph is about the same as soilless. Here is a chart that shows hydro (use the same ph's for soilless) and outdoor mineral soil (really a little high recommended). Click on it to enlarge.

 

Last edited: Aug 17, 2006

M

mace_ecam

Active member

• Aug 17, 2006

• #3

here is a bunch of pH charts, the ones you guys posted are also there:
http://www.angelfire.com/cantina/fourtwenty/articles/nutrientavailability.htm

please keep two things in mind:
- these charts only describe the solubility of certain nutes at a certain pH range, not if they are really taken up
- pH (and EC also) matters in the rootzone, not in the res (unless its NFT/DWC), measure your runoff! Otherwise you still don't know the pH in the rootzone, and thats what matters.

mace

Ps: beware of "information" that uses the term marijuana instead of cannabis

 

T

treble

Active member

• Aug 17, 2006

• #4

thats interesting in that most of the charts showed the same ph for the soil at about 6.5 being dialled in and hydro for the most part about the same.... the only chart showing significantly different trend to this is the color one... I think I have seen that one around before but cant say I noticed the hydro ph that low.

I dont go much below 6.5 and I doubt I could hold it at 5.8 - 6.0 in my res... I dont know but if its correct I will be prepared to try... need to see what the concensus is and look around some more

interesting info .. thanks .. lets see if there is some more
treb

 

Blackmelo

Active member

• Aug 17, 2006

• #5

sproutco, I'm starting to get sick of your constant arguing.
You just seem to want to argue for the sake of it don't you?

Your comments are bs and we have had enough hearing you trying to disagree just to get some attention.

Try saying something positive for once in your life.

 

sproutco

Active member

Veteran

• Aug 17, 2006

• #6

treble said:

I dont go much below 6.5 and I doubt I could hold it at 5.8 - 6.0 in my res... I dont know but if its correct I will be prepared to try... need to see what the concensus is and look around some more

Click to expand...

Hydro in general is 6 to 6.5 with the only plant I know liking lower is lettuce at 5.8 I got this from Hydroponics: a practical guide for the soilless grower by Benton Jones at the Univ. of Ga. I asked Howard Resh, an internationally recognized hydro grower, and he said 6 to 6.5 with the lettuce exclusion too. I like 6 ph for hydro.

Soilless 5.6-6.2 I got this from David Reed at Texas Tech in Water, media, and nutrition for greenhouse crops (ball publishing)

Outdoors in the ground 5.8-6.5 I got this from Clemson Univ.

I need a better chart than the one I presented. I am not really sure about hydro because it has been 15 years since I did it at a university. I don't remember adjusting ph.

Problems really start to happen growing below 5 and above 7.

 

Last edited: Aug 17, 2006

CalcioErba2004

CalErba

Veteran

• Aug 17, 2006

• #7

Ph in hydro should be between 5.0-6.0 Soilless you can drift a little higher, me personally I wouldnt go past 6.5. Run off water in soil shouldnt read lower than 6 or higher than 7.

 

M

meduser180056

Active member

• Aug 17, 2006

• #8

Here's where the chart came from.

http://aggie-horticulture.tamu.edu/GREENHOUSE/NURSERY/GUIDES/ghhdbk/ph.html

I'm thinking 5.8 for soilless since it's inbetween what Sproutco and Varaan are recomending. Over 6 sounds too high, but under 5.6 seems low.

I'll just go with that. LOL Not very scientific, but seems like a good approximation.

 

sproutco

Active member

Veteran

• Aug 18, 2006

• #9

Your exactly right with that ph in soilless. Seems your ph chart may be old thinking or something. Like I said, the newest book about soilless growing from David Reed also at Texas Tech(like your chart) lists what your aiming for.
Here is an article by ohio state that also says 5.5-6.3 http://ohioline.osu.edu/hyg-fact/1000/1252.html

 

Last edited: Aug 18, 2006

M

meduser180056

Active member

• Aug 18, 2006

• #10

Cool sounds like I'm golden then.

Since PH is so critical and most of us take it pretty seriously let me just put a lil reminder out there.

CALIBRATE YOUR PH METER! Do yourself a favor and check it at least once a month.

I hadn't checked mine in months and when I went to calibrate it was .5 off. Sux

This is even more important if your hydro.