Is diatomaceous earth safe for fish and bacteria?

[Chris Smith]

I have been using diatomaceous earth for slug/snail prevention around my troughs with good success. I then noticed it is also effective at keeping out cut worms and ants. I have been experimenting with it and have found it is very affective at killing a wide range of bugs around my yard. I would like to use it on my long term plants in the system for bug control. I have not found too much info on its use with aquaponics.

 

Has anybody tried using diatomaceous earth for bug control in an aquaponic system? Will diatomaceous earth harm bacteria or fish?

[Robert Magnes]

DE is also used as a wormer in chickens, parrots, dogs, cats and other animals. So if you have worms in your grow beds be careful on how much you use. If it can kill tap worms and other bad worms why would it not kill your red wigglers.

[Chris Smith]

Good point, I did not think about DE affecting my worms. I know it is effective in internal pests. I will need to run a few experiments with it on some worms and see how they do.

I have used DE on my chickens to rid then of mites. I dusted our cat because he was tracking poultry mites around and now there are NO flees or mites.

Robert Magnes said:

DE is also used as a wormer in chickens, parrots, dogs, cats and other animals. So if you have worms in your grow beds be careful on how much you use. If it can kill tap worms and other bad worms why would it not kill your red wigglers.

[Chris Smith]

I guess I will have to test DE with gammarus as well as prawns!

[TCLynx]

If dusted sparingly I expect it would be ok.  I believe it is really about the same material that maidenwell is made out of or Diatomite which has a low pH so keep that in mind.  It will also be detrimental to beneficial insects so don't dust the flowers or areas with active ladybugs.

[TCLynx]

In a wet environment I don't think it will be bad for most things.  It is the sharpness of the dust that cuts the insects cuticles and causes them to dehydrate.  I've known of people dusting their worm bins with a small amount of DE on the surface to combat ants and things.  I've used DE as well and it may also have some nice trace minerals to provide to the system in small amounts.

[Allisyn Wood]

@David Lindemann: why do you give your dogs DE? Fleas and ticks?

[TCLynx]

Some people give DE internally to farm animals (as in feed it to them) to help against worms.  Some people even take DE themselves (like mix a spoon of it up in a glass of water or juice.)  Then again, if you eat any commercial grain product, you are probably ingesting DE regularly since they use it in with stored grains to help combat insects in the stored grains.

Keep in mind that food grade DE is different from pool DE since the heat treatment changes the DE so don't sub in the pool stuff instead of the food grade or feed grade DE.

[Aquamaple]

Interesting thread. For those of you in the correct climate, check your local maple syrup supply company for food grade DE. I have not checked pricing, but I know they have it. We mix it with our syrup and then filter it out through a press.

My wife runs a boarding farm and had a boarder put their horse on DE for 1 yr to combat the worms. When She Who Must Be Obeyed started submitting fecal samples to the lab for each horse, they found the horse on DE had more fecal eggs than any other horse on the farm. After one dose of de-wormer, he was back down to the average fecal egg count. My unscientific conclusion: it does not work on all worms. I don't know exactly what this means, but now you know what I have seen.

[Carey Ma]

I've been using DE for years with no negative results except on worms in flood and drain grow-beds. I put it in all my feed to make sure my fish and animals don't have intestinal worms.

*Note DE is a finite resource so it is NOT sustainable.

[Chris Smith]

Carey, how were you applying DE to effect your worms? Were you allowing it to get into the media? Do you think if I used it on top of my rafts that it would get back to the media and harm the worms(we get lots of rain)? I have been worried about DE harming my composting worms in the media beds so I have not used it in the system very much.

[Keith Rowan]

diatomaceous earth and bacillus thurgensis are pretty much the only "bug" controls i use in gb's.. besides sticky traps

[TCLynx]

I know worm farms who would use DE sprinkled on the worm bins to try to control ants so it can't be too terribly hard on worms provided there is enough moisture available for them not to dehydrate from it.  If you let your media beds dry out for a long time between floods, you might need to worry more about DE affecting the worms.

However Chris, what bugs are you trying to control on the rafts with DE?  It is not nearly as effective if it is wet and your daily rains may render it pretty useless against things like ants.