Check this website.

What did you use to create the raised beds?

If you're going to grow vegetables, I don't think I'd add aluminum sulfate. I may be remembering incorrectly, but I don't think you want to add a metal like aluminum in any quantity to soil where you are growing vegetables.

I think you'll also get better results if you add soil sulfur. It works best if you can get it into the soil, rather than simply spreading it on top.

If you can't get soil sulfur, I think you'd be better off adding iron sulfate than aluminum sulfate. The plants are probably suffering from iron deficiency (are the leaves yellow with green veins?).

It would take quite a bit to lower it as much as you want. It's also pretty slow acting. You can probably help a lot by adding a lot of organic matter, but you'll want to stay away from mushroom compost, since it's alkaline.

Thanks Donn and bpgreen for the input Donn I just read that link before I came back to the forum, Thanks. bpgreen, I used lots of mushroom compost to make the soil mix. Maybe thats the culprit. I have 4 large managed compost bins going now (not closed to finished) oak leaves and ucgs might that help later?

What was the source of the mushroom compost?

From what I've read, mushroom compost tends to be alkaline, soif you used lots of it to make the soil mix, that might well be the culprit.

What is the pH in the rest of your lawn? If your soil is normally low pH, the high pH from the mushroom compost (if that's teh cause) could well be temporary. If I were to use something acidic to create raised beds, I wouldn't worry about the acidity, since my soil is naturally alkaline, so any acidity would be short lived.

The compost you're making should help, as well. It will probably turn out fairly close to neutral, but that'll bring the total pH closer to neutral, and more OM will help buffer the alkalinity..

Where are you located? If the zone 8B is in the deserts of CA or AZ, you probably started with alkaline soil, but if you're in an area with lots of rain, you're less likely to need to worry that the alkalinity is a long term issue.

Hey bpgreen, Thanks again for the reply. I do not have any idea what type of mushroom compost I used, it was two differet brands.
I live near Charleston SC. One thing that I didn't mention is that the "soil" in these beds is artificial IE peat moss vermiculite and three types of store bought composts. I read a book about square foot gardening and used that store bought mix to make framed raised beds. The native soil here I have not tested but grass and trees grow well so it probably is not a matter of the native soil. Since compost is brewing I'm not that worried about the raised beds in the long term, however everyboby thinks I'm a wacko so a good crop of veggies this summer is essential for my short term status as someone with a goal.
Thanks, Tim

One of the things the Master Gardners are supposed to learn is how and where to look up information. We were repeatedly told that during my MG and AMG classes. That is one of the reasons we received a very thick and heavy textbook as well as access to the Extension Service library. Since that "Master Gardener" did not know the answer to your question and apparently could not find that information tells me there is a very large lack of education in that program, or that "Master Gardener" did not pay attention during class (a common problem. I have heard of some programs where people that never attended a class certified that student).
How much of what you add depends on where you are and zone 8 in the United States is not very helpful. Which state, maybe even southwest someplace, would provide the information needed to answer your question.

University soil sites such as Clemson sometime recommend aluminum for changing soil pH. On the other hand I quote from link below: only because it is a concise statement of my recollection of my soil science class decades ago.

"Aluminum occurs in large amounts in all soils in the form of undecomposed minerals, and in the inorganic colloidal materials. In neutral, slightly alkaline or slightly acid soils, the element is in inert combinations that have no effect on plant growth. At greater degrees of acidity, aluminum becomes active, capable of combining as soluble salts, and thus exerting a toxic effect upon the growth of many plants, especially those that are benefited by liming, when grown on acid soils. A high, or very high, test is a certain index of an undesirable acid soil, upon which acid-sensitive crops are almost certain to fail. A medium
test is not so serious, especially with grasses, corn, oats, potatoes and tobacco. A low, or negative, test is desirable, except for distinctly acid-tolerant plants"

I am not sure I would try and change the pH this first time around. Many of these tests and suggestions are given by professionals for professionals and for cases where a profit margin is important.

Here is a link that might be useful: Aluminum in soil