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Novice PH question

overload

New member
Hi, i have a basic question about how to figure out the PH in soil.

I simply cant figure out how to check the PH in soil. If i water with tap water @ PH 8 and the run off is Ph 7, what does this mean? :dunno: is my soil ph 7 or is it much lower, around 6?

Having some troubles with some big and small brown spots on younger leafs and i don't know what this is so i want to start with checking the ph levels.
 

itz4me123

New member
Buy some potting soil with the right PH, either top you soil with it or transplant into new soil. I hope that helps you, bro.
 

Granger2

Active member
Veteran
Overload,
Get some Citric Acid [Earth Juice pH down] and pH your water/nute mixes to where you want it. That will probably improve things. Water with a pH of 8 is no good. Good luck. -granger
 
S

Sat X RB

you are on the right track by checking yr pH as a first step!

but you needed to know yr soil pH BEFORE you planted. that way you may only need to check once thru the grow.

I only ever use a "soil pH test kit". very cheap and accurate ($16 in this country) from yr friendly hardware/nursery.

you need to know some theory about soil pH. the ideal is supposed to be 7. that figure is considered to be 'neutral' altho cannabis likes closer to 6.5.
acid soils are those numbers BELOW 7. alkaline soils are those numbers ABOVE 7.

each number is twice the acid/alk of the number before. so that means two points out means four times difference (dig?). so two points out is A LOT!

as ferts are added soil in pots will increase in acidity. this is why you may need to check halfway thru a grow.

if you need to alter pH to a higher number use Dolomite (because it contains Magnesium as well as Calcium). if you do this to yr potting mix before you plant ... Dolomite (or lime) will take a fortnight to do its thing. altho if you need to alter yr growing medium while there's a plant in it you can sprinkle Dolomite on LIKE SUGAR ON A DONUT NO MORE! and water in. wait a few days before applying more. be cautious with this because over liming is harder to fix than over acid.

blah blah blah hope that helps ... cheers from the Land of Oz.
 

overload

New member
Thx to everone for giving me some guidance :)

I did some flushing and sprinkled some dolomite on the soli, but have to wait a week or so before the soil dries out a little before i can water with nutes again. should i correct the water ph to 6.5?

I bought a cheap Chinese soil ph, temp, light instrument, it shows a ph around 6,5-7 now after flushing.. but i cant trust this piece of shit.

Been researching a little what kind o problem this is by comparing to "Joe's Fresh Guide to Sick Plant Diagnosis" and so far it looks like nute burns or calcium deficiency.

Have 4 strains in my tent and these are, G13 Labs OG13, World of Seeds Legend Collection Mazar Kush, Barneys Farm Critical Kush and Dinafem Seeds Cheese. Only Critical Kush loolks healthy, mazar looks ok too, og13 is worst.

Now in week 4 of flowering, looks like there has not been any progress growth vise on the buds for a week. Im devastated because this is my first grow and its very important for me. Got diagnosed with MS last year and i want to try if cannabis would help me a little to loosen up my muscles. Im from sweden and here cannabis is a BIG no, no- but my doctor told my of the books that cannabis maybe could help a little.
 

Gelado`

Active member
Veteran
I use an aquarium liquid pH tester. It's very accurate and cheap too. Are you talking about the cheap Chinese testers with a metal prong (stick)?

Since you're a newbie, overfertilizing is far more likely. What kind of fertilizer are you using?
 

overload

New member
I use an aquarium liquid pH tester. It's very accurate and cheap too. Are you talking about the cheap Chinese testers with a metal prong (stick)?

Since you're a newbie, overfertilizing is far more likely. What kind of fertilizer are you using?
Last one i bought was as you said a tester with a metal prong, i also have a normal digital liquid ph tester.
 

overload

New member
Have been using nutes from Gold Lable http://www.goldlabel.nl/ in week 3 of 5 in veg i started using a little, around 1/2 to 3/4 every second watering. maybe too much, tried to be cautious.

Have been thinking that i should bought some organic nutes insted..
 
whether using a cheap chinese pH tester or an expensive one, the calibration solutions offered (amazon) are a great asset. The more expensive testers have a calibration function so you just "test" the calibration solution (known at pH 7 for example) and hit "calibrate" on your tester and it will adjust to show 7. But even if your tester doesn't have a calibration function, the solution will give you an idea of whether your tester is reading high or low and at least know if your tester is showing 7.5 when in a known solution of 7.0 that your tester is reading .5 high ..... hopefully you get the idea

my bud gave up on the cheap tester he had and bought a good one from Hanna (iirc) and he still has to calibrate it once a week or so
 

Gelado`

Active member
Veteran
You can also test the pH of household chemicals if you don't have calibration fluid around:

http://answers.yahoo.com/question/index?qid=20080521063327AAGrXNa

Whatever it says on the bottle on chem nutes, use 1/4 strength so you don't mess your plants up. I recommend picking up a cheap bottle of phosphoric acid pH down to get your pH where it needs to be. I use two drops per liter and my plants are thriving. My pH is about the same as yours out of the tap.
 

overload

New member
Bought some ph up and down so now im able to adjust my water.

Today after 1 week of waiting the soil for Critical Kush was dry enough to water, used half strength. Ph was 6,4 and ec around 850. runoff was ph 7,4 EC 1,2.

The runoff water was all white so i guess i sprinkled too much dolomite. Hope i don't mess everything up now, only 3-4 weeks left..

Also the flowers start to smell really much now, good that i have a carbon filter. My wife asked if im using a new fragrance on my cologne :)

Im thinking i of using a set of working clothes when im in my "man cave" in the garage, working with my plants otherwise people start suspecting something i going on.
 

Gelado`

Active member
Veteran
If you have too much dolomite in your medium I would suggest flushing with water at pH 5.5 or so.
 
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