Hints on measuring PH

[danw]

This is my first year with blueberry plants, and I am having some trouble measuring the PH of my planting media. I have a soil test kit that includes PH but it does not work on my blueberry soil. My test kit uses a solution you mix with a measured amount of soil, shake then wait for it to settle. The solution includes a PH indicator and it works great for my garden / dirt. However the blueberries are planted in an Azalea mix to which I added some additional soil sulfur. The Azalea mix is very coarse sawdust like and never settles in the solution, or turns the solution black, rendering the test useless. I would rather not have to purchase some expensive meter, and I am wondering if I might have better luck with a test strip type of measurement.

Thanks,
Dan

[Blueboy1977]

If you have access to sphagnum peatmoss, ninebark mulch and a way to collect rain water you won't have to worry about pH. That's a fail proof way to grow them. Having to measure soil pH and chase them from one pH to another will eventually lead to a few losses. Especially if using sulfer to acidify. It can take months for sulfer to change soil pH and to heavy of a hand will drop the soil pH entirely too much. I'm speaking from experience with pot grown plants. In ground plants are another subject. When I first started I used tap water and sulfer in my pots. The only way I could find to get accurate reading was to use the glass bulb type liquid pH meters. I would buy a few gallons of deionized or reverse osmosis water and flood the pots then test the water as it poured out the bottom of the pots. If a plant was suffering visually it was almost always pH issues and was confirmed by this testing method. I had a bunch of pots that were in the low to mid 3 pH range and had to flush with tap water for a couple hours to get them back into range. It was a hassle to say the least! Then came the rain barrels and I haven't used sulfer or tested pH in 4 years now. Take that back, I have a fertilizer that has sulfer in it and I only use it if I notice the new leafs getting chlorotic. A light dose of that I'm good for several more years. Only had to apply that to a couple plants last year. All is good.

[danw]

Thanks for the info.

As you inferred, I am doing exactly what you referred to. Growing in pots adding sulfur, and I am flying totally blind. The potting mix I started with was supposed to have a PH around 5.4, so I reasoned I should add some undetermined "handful" amount of sulfur to get it under 5. My water is around 6 and I used one dose of "Dr Earth Acid lovers" starting out and use 1/2 tsp AS / gal every month. At this point I have absolutely no idea what the PH is, but the plants seem to be doing fine. They are all putting out new growth and leaves. It is too late for me to collect any rain water this year but I will keep it in mind for next year.

So you feel that collecting the water that drains through the media is a good indication of the PH of the media? I guess that makes sense, it is similar to the PH test I have now, but the drain water is probably cleaner than the shaken solution in a test tube.

[Blueboy1977]

The key here is using deionized water or reverse osmosis water. It will take on the pH of the soil media as it pass through it.

[stevel]

I also am growing in pots. The first few batches of potting mix I added sulphur, but after learning more decided to omit the sulphur because it would be very difficult to reverse the process if it got too acidic. I am using pine bark, peat moss, and perlite for my mix. Using rain water, everything was moving along just fine. Ran out of rain water started using acidified tap water and over did it, the plants let me know pretty quickly so I went to straight tap water and within three days saw much happier plants. I think I also over fertilized once and it showed right away also. It seems they react very quickly, within 12 hrs to three days, to changes in the soil condition. Some seem to be much more sensitive than others.

[WillsC]

Dan,

This may not be something you want to do but......if you send me a soil sample 1/2 cup I would be happy to test it for you.

[danw]

Thanks for the kind offer Wills!

I am actually just going to bite the bullet and purchase a meter. Some of my other hobbies would also benefit from the use of a PH meter. I make hard cider and also do a fair bit of brewing. The cider making especially will make good use of an accurate PH meter.

If I may ask, what method do you use to measure the PH? Is it similar to Blueboy where you use DI water with a soil sample then measure the drained water? Also what meter do you use? I assume most of the fairly economical units would work fine for soil tests.

[WillsC]

Sadly the cheap PH meters are mostly garbage. I use a Kelway direct read meter but it is not usable in liquids.

[danw]

Hmm that Kelway looks interesting. I need to read up on the working principle.

[WillsC]

It works flawlessly. It is just electrical conductivity.