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Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 8:04 am
by Setec Astronomy
I grow mostly in containers, and have been trying to get an idea of my pH, particularly in my pea planters that I have been having some trouble with, and also in my strawberries, to see if they are acid enough.
I have a single-probe soil pH meter I bought a few years ago for my lawn, and I bought some fancy soil pH test strips with 3 pads on each strip. The test strips called for 8 tablespoons of soil, 8 tablespoons of water, let sit for at least 1 hour, preferably 8 hours, that all sounds crazy to me (more sample than needed, way more wait time), but whatever.
I mix everything up, put the test strip in...I get 8.0. So I stick my pH meter in the solution--it reads 7.0, which is what it always reads, which is why I bought the test strips. So then I realize I have some regular pH paper, so I stick that in...that reads 6-7. So I don't know what I have.
I see in another thread in this sub-forum it seemed people were sending soil samples to a lab--what are the rest of you doing for measuring pH or other soil analysis?
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 11:01 am
by Vanman
I get a soil sample box from the county agent and send it in every two or three years. Costs $15 and they send back a report that covers everything I need to know as well as recommended fertilization for various garden crops.
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 7:28 pm
by Whwoz
Setec Astronomy wrote: ↑Tue Feb 15, 2022 8:04 am
I grow mostly in containers, and have been trying to get an idea of my pH, particularly in my pea planters that I have been having some trouble with, and also in my strawberries, to see if they are acid enough.
I have a single-probe soil pH meter I bought a few years ago for my lawn, and I bought some fancy soil pH test strips with 3 pads on each strip. The test strips called for 8 tablespoons of soil, 8 tablespoons of water, let sit for at least 1 hour, preferably 8 hours, that all sounds crazy to me (more sample than needed, way more wait time), but whatever.
I mix everything up, put the test strip in...I get 8.0. So I stick my pH meter in the solution--it reads 7.0, which is what it always reads, which is why I bought the test strips. So then I realize I have some regular pH paper, so I stick that in...that reads 6-7. So I don't know what I have.
I see in another thread in this sub-forum it seemed people were sending soil samples to a lab--what are the rest of you doing for measuring pH or other soil analysis?
That amount of sample and wait time may seem ridiculous, but it is to do with the variable nature of soil and ensuring that the sample is fully wetted out and the solution has an even pH across both soil and water parts. With knowing anymore about test kits (have not come across anything similiar Down Under yet) I cannot say anything specific. Ideally with soil you want a slurry that has no standing water or dry parts in it. Can be difficult to achieve in some soils so you give it a longer time. Don't forget that the pH of your water may not be 7 and this will influence the result slightly.
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 7:39 pm
by Cole_Robbie
The probe ph meters for soil are not worth your time.
You can get an idea of whether you are too high or too low in pH based upon the nutrient deficiencies that the plant exhibits. Every nutrient has a pH range in which it may be absorbed by the plant. If your plants are healthy and green, then your pH is fine.
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 7:50 pm
by Setec Astronomy
Whwoz wrote: ↑Tue Feb 15, 2022 7:28 pm Don't forget that the pH of your water may not be 7 and this will influence the result slightly.
They suggest distilled water for best result, I used tap water that gave me about the same pH with my paper as the sample...which maybe means that the soil test strip IS accurate--only because it didn't give that same result. I should read the info pamphlet some more.
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 9:15 pm
by Whwoz
Setec Astronomy wrote: ↑Tue Feb 15, 2022 7:50 pm
Whwoz wrote: ↑Tue Feb 15, 2022 7:28 pm Don't forget that the pH of your water may not be 7 and this will influence the result slightly.
They suggest distilled water for best result, I used tap water that gave me about the same pH with my paper as the sample...which maybe means that the soil test strip IS accurate--only because it didn't give that same result. I should read the info pamphlet some more.
Even distilled water is only as good as the water from which it is derived, if not pH balanced before distilling then pH afterwards will not necessary be 7. Have seen distilled water with pH ranging from 5 to 8 at different times, depending on source water.
Re: Soil pH, Testing, etc.
Posted: Tue Feb 15, 2022 10:40 pm
by Cole_Robbie
Pure water is ph 7, but when exposed to air absorbs carbon dioxide, dropping the ph. This link says pure is often 5.8 ph
https://sciencing.com/ph-distilled-water-4623914.html
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 6:48 am
by bower
I've never managed a test setup, so I do like Cole, look for signs on the plants. Red leaves means acid ground. Around here the sorrels are a good indicator. Also moss is reliable, means the ground is acid. When algae starts to grow on the surface of container soil, I know it's acid. I sprinkle some lime on and scratch it in. Algae disappears.
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 7:02 am
by brownrexx
I get my soil tested every couple of years at the PA State Ag Lab for $9 plus postage to ship it to them.
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 7:03 am
by Setec Astronomy
Bower wrote: ↑Wed Feb 16, 2022 6:48 am
I've never managed a test setup, so I do like Cole, look for signs on the plants. Red leaves means acid ground. Around here the sorrels are a good indicator. Also moss is reliable, means the ground is acid. When algae starts to grow on the surface of container soil, I know it's acid. I sprinkle some lime on and scratch it in. Algae disappears.
Ohh...I definitely get moss growing on the surface of a lot of my containers...but how acid is acid? For instance, Johnny's Seeds says peas grow best in pH 6.5-6.8, which is acid, although only slightly so. Does it have to be more acid than that for moss/algae?
The potting mix I've been using the last couple of years says it has as an ingredient "limestone to adjust pH", so I'm presuming it's naturally acid
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 7:04 am
by Setec Astronomy
brownrexx wrote: ↑Wed Feb 16, 2022 7:02 am
I get my soil tested every couple of years at the PA State Ag Lab for $9 plus postage to ship it to them.
I'm looking at what I have to do here in NJ to get a sample tested at Rutgers...but I'm stuck in a circular web-link reference.
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 8:43 am
by bower
Re: moss. Just googled and the preferred pH for moss is 5 to 5.5.
Peat is naturally acidic. All the mixes involving peat have lime added to adjust for that. It's not always well mixed though.
The other thing is that watering - or rain - or waterlogging - causes the pH to fall. And this is where you get moss at its happiest, with excess moisture to feed on in a damp space that continues to acidify as you water it all season.
I just read on my google that moss will grow in alkaline conditions as well. But that would be unusual, afaik.
I can tell you that a handful of crumbled lime over moss or algae, it doesn't stick around. not liking a pH bump from the lime at all, in my experience.
Re: Soil pH, Testing, etc.
Posted: Wed Feb 16, 2022 9:00 am
by Setec Astronomy
Well, that makes me even more confused about my test results, but I may try that moss/lime trick on my driveway
