Soil mix too alkaline, 8.0!!!

so I made my own soil mix and after it’s been “cooking” for almost two months now is showing a ph of 8.0. The last time I tried using an alkaline soil it caused all sorts of lockout issues and I knew it was front too much oyster shell and the diatomaceous earth with bentonite clay being alkaline.

This time I used
.5 cu/ft of coco,
.5cu/ft of promix organic,
.25 cu/ft of ancient forest
1cu/ft of growstones
2cups of dr earth bloom
1cup alfalfa meal
1 cup espoma chicken manure
.5 cup high N bat guano
1 cup glacial rock dust
1 cup gypsum

The only lime would be in the promix organic potting soil so why would my mix have such a high ph?

I have a soil acidifier but am hesitant to use it and I also have soil sulfur but that would take almost a year to be of any help. Any organic ways to get my ph down or is the “non-organic” soil acidifier my only option?

What did you use to test the pH? I really see nothing to cause such a high pH and I'm wondering about the accuracy of the test.

Coir in a LOS soil can cause problems with leaching due to microbial activity, but IDK about it affecting pH. The one person I know dealing with alkalinity issues uses garden sulfur for lowering the pH.

Wet

Well I originally used the water drops to get the 8.0 ph. I would take 1 part of the soil mix and add 2 parts water mix and let settle. Once the debris from the soil settled to the bottom I would take 10ml and add one drop of the red liquid, shake and compare the color.
This ph test has always worked well for me and while it didn’t give me a very specific, exact ph, it let me know the range I was working in and had never had issues. The old soil mix that this test said had a high ph gave me issues with the plants that were so much of an issue to deal with I ended up cutting the plants down and getting some “hi-yield iron and soil acidifier” and “soil sulphur” to add to the soil and recook it until the ph dropped and then that soil mix worked fine.

Anyway so I had used my usual liquid ph test yesterday and it showed that the ph of this current mix was 8. So this evening i saw my mom had one of those “rapidtest ph meters” they sell at Home Depot or Lowe’s or some big box store. So since she no longer does potted house plants she said I was welcom to have it. I got home and stuck it in the mix, waited the minute or so it says to wait for it to get the correct reading and looked and it says the soil mix has a ph of 6.3.
So I know it’s not one of those top of the line ph pens everyone will say I should get but it does have a digital display and after using the liquid drops to test my tap water I realized that the liquid test results were probably high because my water which is normally a little over a ph of 7 is suddenly reading at 8.5-9 with the liquid drops.

Drops are the best, the only flaw is it relies on your own ability to compare against a chart.
If I liked pH pens, I'd still use drops to compare against it's results.

Well the other issue with drops is the source water, which appears to be my issue. I’ll grab a gallon of distilled water and use that to test the soil in a few day

Honestly i think it comes down to this: ph testing a new mix is not very accurate. I had my mix test at 7.8ph. I decided to trust the recipe and everything went great. No ph issues showed on the plants and the yield was better than expected. The reality is your soil mix consists of multiple ingredients that all have differing ph values. These ingredients dont just combine to form one ph value in the planter.
Also your water ph can change day to day and even hour to hour depending on the source. I see my water ph change during spring runoff especially.

Yeah I have well water and while most of the time it’s stable in the 7-7.5 range, it does have its times where it goes higher, but never lower.
I also live around a lot of farm land and also a public lake all within a mile. I’ve been wanting to have a mineral analysis done on my water to see what’s actually in it beside the obvious calcium. I wouldn’t be shocked to find out my water has a low NPK with all the runoff from the farming.
The only real test I’ve seen for this is for Home brewers. I’m sure I could have the test I want done no problem, but cost will be the main factor. I’m curious but not curious enough to spend hundred or even thousands of dollars to get a full detailed analysis of my well water.