After paying $30.00 a pound for humic acids for my soil, I recently purchased some for $16.00 for 32 pounds. It seems the same when mixed with water. I did some research using an old tag on one bag, and found a mine close to me which apparently supplies the stuff to an awful lot of nurseries in the Southwest, where you can buy the material by the ton.
My question is this, does anyone have any long term experience with this material and alkaline soils?
Next, how much of this material is too much for alkaline soils at 8.0 PH?
I don't know about your soil, but acidifiers don't work well here. We have alkaline clay that is formed when our chalky shale breaks down, and there are bits of shale in it. It is described as having a lot of "free lime", and it fizzes when you pour vinegar on it. I would describe it as being "buffered". When it fizzes, the little bits of shale are breaking down further. When it stops fizzing, the pH is back pretty close to where it started.
If your bulk product is a by-product of mining, you might want to have it tested for undesirable or excessive metals.