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?

[Carey Ma]

@ Chris S: Sorry mate, I should have phrased my statement more carefully. I should have said that there might be potential harm to worms in media because of the physical nature of DE. One time, many years ago, I had DE lining my media bed to prevent critters from eating up my crop, which became a smelly mess a few days after a heavy rain due to massive worm die out. But I was too inexperienced to tell whether it was from too much DE being washed into my system or due to other contaminants being washed in (I had sulphur mixed in) . 

I read a report that our intestines suffer a bit of damage when ingested so I just assumed that due to the physical properties of DE, it would be potentially harmful to any insect. It would be worth it if someone could do a small test to determine this question. Maybe earthworm skin is tough enough to handle the extreme abrasion.

[TCLynx]

I've had to dust my worm bins with DE powder a few times when ants managed to get in.  Granted I wasn't washing huge amounts of the stuff into the beds, just dusting the top but eventually rain did wash the powder into the worm beds and as far as I know it didn't greatly impact the worm population.

DE dust is sharp, it would be bad to breath a lot of it or get a lot of it in your eyes but that is the same with any type of dust.  I've ingested a large heaping tablespoon full in 16 ounces of water before with no acute ill effects that I could tell.  Maybe it is abrasive to our insides but the food grade stuff isn't going to kill a person who eats it.

[Jim Fisk]

In my battle with what I now believe is an infestation of fungas knats I read that Diamatious Earth worked into the soil will kill adults and larvae. I am wondering if it is safe in my gravel grow beds for fish. Anyone tried it in this manor. Fly traps are going gangbusters but I really want to get a handle on this before Spring planting in a few weeks.

I see that TC likes to test things on herself first but then fish may feel differently

[veronica moore]

What is diatomaceous earth?  Is it sold in Hi? I can't work outside because the ants eat me too much I don't want poison, but that earth sounds promising?  Veronica

[Robert J]

Folks,  Check out LDSprepper on youtube. he's identified the DE that is natural and works will with us and that which is not.  The DE used for Horses is good for the garden, the other is not.  Unfortunately, I don't know which is which.

[Verna Gross]

I've been using DE all summer and have almost totally elevated Aphids. No side effects at all I not only sprinkle it around bottom plants but dust it in my pepper plant leaves

[TCLynx]

DE or Diatomaceous earth is a powder made from the fossil remains of Diatoms where were microscopic sea creatures.

To be safe look for food grade Diatomaceous earth.  Sometimes feed stores carry it.  Avoid the stuff they use in swimming pool filters and avoid the stuff that has anything else added to it (sometimes it is sold in the pest control aisle and that stuff, who knows what else they have added so it might be safe on the ground around your system but I would go dusting it into your system since there might be other pesticides mixed into it.)

Drawback with DE is that once it gets wet, it is fairly ineffective against most pests and Aquaponics is a fairly wet environment.  See the dust works by being sharp and cutting the insects so that they dehydrate to death, in a moist environment they often have a change to recover.  I expect it would be most effective around a system that doesn't get rained on so it can be kept dry.

FYI if you have ever eaten any grain products or cereal, you have eaten DE.  Food grade DE is often put (at up to 2% by volume) into grain storage to control pests like weevils in the grain stores.  So if you have ever eaten grain that is grown and stored before being turned into the final products, you have eaten DE.

[veronica moore]

Well thank you for all the information.  It rains everyday where I live so I won't be using any of that stuff. 

[Robert J]

You may want to checkout Brightagrotech on youtube.  Nate Story has a couple really good videos on integrated pest management.  Also, if you can buy ladybugs where you are (you might also need bug feed too), they and the praying mantus are awesome for aphids.  Though I have not tried it, and am leary I've read that a diluted solution of Dawn dish soap works well too.

veronica moore said:

Well thank you for all the information.  It rains everyday where I live so I won't be using any of that stuff. 

 

[TCLynx]

Soap kills fish!!!!!!  If you are going to spray with anything that might be dangerous to fish, make sure your fish tank is covered and put drop cloths down around the plants so any dripping doesn't get into the grow beds.  (This might not be safe to do if your plants are out where rain could later wash soaps, oils or any other spray that might be dangerous to fish down into the system water.

Be very careful with anything with soap around your AP system.

AND

for your fishes sake, don't mix up your solution on your grow beds or anywhere near your system!  I know plenty of people who figure they are safe if they are only using one drop or soap or oil per gallon of spray but I've also heard of some one having the jug of soap sitting on the grow bed with the top open and while they are looking the other way spraying the plants, the kid or dog comes by and knocks the jug over and it pours into the system!!!!!!!!!