Avoiding acid in worm beds.

by David
(Liverpool, NSW, Australia)

happy worms

happy worms

I've seen cautions many times about not feeding citrus and several other foods to compost worms because of the acid problem.

I've always fed any vegetable matter I can find, in moderation, and my worms are still doing fine ten years on.
But, if feeding known acidic foods, I always add a few eggshells crushed and sprinkled in with the feed.
Crushed eggshells will always assist in keeping the acidity low.
Gardeners' dolomite, snail shells, seashells (rinsed to remove the salt) or chalk will do the same job. Also dark green vegetables such as broccoli and kale contain significant amounts of calcium carbonate.
So, it's not really difficult to avoid an acidic worm bed while feeding almost anything.

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Feb 12, 2015
by: Ken

Well, that is actually new information to me. I didn’t know that putting citrus content items in the pit can actually deteriorate the quality of the compos. And what if I have added any like that and how would I compensate for such act.


Hi Ken,

you can through some agricultural lime on the surface of your worm bin as this can counteract acid build up in you worm farm.

In future only add small amounts of citrus fruit peels to your worm farm to avoid acid build up in the worm bedding

Kind regards

Stephan Kloppert
Author of "How to start a profitable worm business on a shoestring budget"

Feb 11, 2015
Acidity in worm farms
by: Ingiya

Thanks for the valuable information to avoid acid build up in worm farms.

Apr 13, 2013
re: feeding Acidic foods to worms
by: Anonymous

Hello David,

sorry for my late reply I am busy finishing my first book about worm composting as a business and have to catch up now with submissions to the site!

Thank you for your excellent contribution! I totally agree with you it is not that difficult
to feed acidic materials to a worm farm is one does it in moderation!

I love your suggestion of adding some things like Crushed eggshells, Gardeners' dolomite, snail shells, seashells (rinsed to remove the salt) to the worm bin to assist in balancing the "ph" levels inside the worm bin!

I feed all citrus fruits as well as cat poop to some of my worm farms and had no problems at all!

As you mentioned the secret is to do it in moderation! As long as the worms have enough bedding inside their bin that they can retreat to without being burnt up it will be just fine!

The worms can than just move towards the acidic food eat some of it and move away again!
I fed some of my worms exclusively orange peels for a while and they finished them off without problems!

I believe one of the mistakes people make when feeding acidic food to their worms is to add the acidic waste first over the whole surface of the worm bin and than they pour water over it!

The water will than pick up some of the acidity and spread it throughout the bedding with no place for the worms to hide.

I really valued your input David and you are more than welcome to share more of your worm farming experiences! I am sure many of our visitors can greatly benefit from it!

Kind regards


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