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How Do I Raise the pH of My Compost?

by Gene

What can I add to my compost to raise the pH?

Comments for How Do I Raise the pH of My Compost?

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Oct 15, 2011
A Few Suggestions…
by: Compost Junkie Dave

Hi Gene,

Thanks for your question.

What materials did you use to build your compost pile?

Depending on the ingredients, the pH of compost tends to raise during the composting process (heating phase) to approximately 8-8.5, but may then fall to around 7.0 during the cooling phase.

If your initial ingredients included a lot of fruits and veggies, the pH will tend to be quite acidic (below 7.0 on the pH scale). To remedy, I’d add a high quality calcium source, or wood ash, to your mix while building the pile.

Ideally, I’d recommend using our Recharge product, but it’s going through its final packaging stages and isn’t ready yet. So for now, check out your local garden centers, or farmers co-op, and try to locate agricultural lime (aka calcium carbonate and/or high calcium lime). Agricultural lime will provide you with an increase in pH while minimizing the addition of other elements to your compost. For instance, bone meal is also a good source of calcium, but it also contains a significant amount of phosphorus. Dolomite lime is also a good source of calcium (and is readily available), but it contains a decent dose of magnesium. If you’re in a real pinch and can’t find Ag lime, try one of the others.

Hope this helps.


Oct 18, 2011
Compost pH
by: GENE

Thank you CJD. I shall give your comments a try. [good info]

Jul 27, 2013
What is the ideal ph for compost tea being used outdoors in soil.
by: Will

I have found a great deal of information here, howerever I don’t seem to find what the ideal ph should be in my brewer. This tea is used outside in soil. While my garden is responding very well, the ph of the tea in the brewer is 5.6. Would you use solids like ag lime or a liquid like Ph Up?

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