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How can I tell what my medium ph is?

papa canna

Well-Known Member
I'm growing in sunshine advanced #4 which is mostly peat moss mixed with a bit of coco and a couple of goodies. The bag claims that it is pre-ph'd to 5.8-6.5 But i've been reading lately about people talking about how peat can be a bit acidic. Is the only way to check the ph of my medium by testing the ph of my run off water?

i've been watering with 6.4 water and just want to double check that I dont have any ph problems because im pretty sure my girls are having a nitrogen deficiency while im in the third week of flower. But I just wanted to double check that there are no ph issues.

edit: also, what should my run off be if im growing in peat moss?
 

jarvild

Well-Known Member
Don't know what goodies you put in but you're a little high on your pH for soil-less.
Yes peat has a pH of around 4.9 but they lime it to stabilize it.
Slurry Test or Plug test is the only way to get a accurate reading on soil pH.
Not unusual to see nitrogen def 3rd week of flower. If it's to bad feed it some grow.
 

papa canna

Well-Known Member
Don't know what goodies you put in but you're a little high on your pH for soil-less.
Yes peat has a pH of around 4.9 but they lime it to stabilize it.
Slurry Test or Plug test is the only way to get a accurate reading on soil pH.
Not unusual to see nitrogen def 3rd week of flower. If it's to bad feed it some grow.
I've been giving it a small amount of veg nutes in addition to the bloom. But I dont know what slurry or plug tests are.
 

jarvild

Well-Known Member
Remove some soil from the root zone and mix it 2 parts water to 1 part soil and check pH.
Google is you're friend. I don't mind helping but you need to do a little research on you're own. If you have question after that I'll be more than glad to help you.
 

Grojoe90

Active Member
I'm growing in sunshine advanced #4 which is mostly peat moss mixed with a bit of coco and a couple of goodies. The bag claims that it is pre-ph'd to 5.8-6.5 But i've been reading lately about people talking about how peat can be a bit acidic. Is the only way to check the ph of my medium by testing the ph of my run off water?

i've been watering with 6.4 water and just want to double check that I dont have any ph problems because im pretty sure my girls are having a nitrogen deficiency while im in the third week of flower. But I just wanted to double check that there are no ph issues.

edit: also, what should my run off be if im growing in peat moss?
There's a tool you can grab probably at most hardware stores that measures the ph of your soil, and also measures the wetness. Comes in great use when you need it. No more than $10
 

papa canna

Well-Known Member
There's a tool you can grab probably at most hardware stores that measures the ph of your soil, and also measures the wetness. Comes in great use when you need it. No more than $10
While that sounds handy I would question the reliability of a cheap hardware tool, but I will look into it
 

papa canna

Well-Known Member
Remove some soil from the root zone and mix it 2 parts water to 1 part soil and check pH.
Google is you're friend. I don't mind helping but you need to do a little research on you're own. If you have question after that I'll be more than glad to help you.
I will start googling as soon as I get off work. On a side note, won't the ph of your water throw off the ph of your medium?
 

papa canna

Well-Known Member
Well drop 100$ on one that comes in a fancy case. Or take your hydro store guys advice when he says you NEED his 250$ test kit.
They work just fine though. On a side note you can usually find digital probes at greenhouses
I have a good water ph meter, but I don't suppose that will do it in this case
 

papa canna

Well-Known Member
I grow in sunshine mix #4 and have never needed to check the PH
I have 2 strains that are yellowing up on me a little bit, so i just wanted to check to be sure. Its probably a nitrogen deficiency, but i've been giving them nitrogen for 2 feedings and im still getting yellowing. should I add a bit more? My mentor says that it was because my light was too close to the tops. They were about 12 inches away, and i moved them up a little bit. Although I'm still leaning towards nitrogen deficiency, it would make sense cause the most affected plants are the ones closest to light
 
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