is diatomaceous earth bad for composting worms (red wigglers)

I am raising worms right now to eventually feed my chickens and I am curious to know if DE is bad for red wigglers? If not I would encourage my source of horse manure to use it in the feed instead of commercial de-wormer and I would also use my chicken manure \ bedding \ DE in my worm farm. Thanks.

YES. D.E. does kill the bad guys, but being nondiscriminatory, it also kills the good guys.

There are worming medicines that do kill the bad guys in an animal's gut, but are harmless once passed through the animal's system. D.E., on the other hand, passes through the system unchanged. It is just as lethal in a pile of shit as it was in a pile of food.

No, DE run through a horse as a dewormer does NOT hurt Earthworms. Different kind of worm. You do need to use food grade though. That is important for both the horse and the earthworms. PS Earthworms actually eat DE and use it for grit in their digestive systems. Ironically they are attracted to it. Certainly doesn't harm them.

Scott Strough wrote:No, DE run through a horse as a dewormer does NOT hurt Earthworms. Different kind of worm. You do need to use food grade though. That is important for both the horse and the earthworms. PS Earthworms actually eat DE and use it for grit in their digestive systems. Ironically they are attracted to it. Certainly doesn't harm them.

I agree with Scott. I use DE in my compost piles and the earth worms thrive just fine. I have several types including night crawlers and the red wigglers.
Btw, when using horse manure, make sure you let the compost pile sit for a week and cook before turning over. The horse does not thoroughly digest whole seed and the seed may germinate, thus creating unwanted weeds in a garden.

I use DE in my chicken coop and I toss the bedding in an unused raised bed. There are a crap ton of red wigglers right underneath the surface and even other insects as well. I believe the DE must get buffed after a while from being mixed in or something.

DE has edges like sharp knives, and worms stay away from that.  There is that science tidbit about things break down in the same shape no matter how small the particles.  So if something appears in angular pieces with sharp corners when smashed, no matter how much you smash it, those pieces will always be that shape.

If the worms are surviving, then they are finding soil to pass through themselves that doesn't contain it or contains very little, which is the only way they eat.   Or they are finding enough of what they need to reproduce, which is quite quickly, something like 4 to 6 weeks?  and it looks like they are surviving, but it's new worms.

If DE is in the soil, or egg shells, or sharp beach sand, worms will avoid them.  You can't take them back out of the soil, so they are a long-term thing.  There are other soft-bodied soil friends we need who also stay away.  They affect the balance of things.  It isn't just about worms.