The Great D.E. Thread

Hey All,
I wanted to start a thread dedicated to the discussion of D.E. and D.E. alone. People can share their experiences with it, thoughts and opinions on different brands and suppliers, and any horticultural knowledge pertaining to diatomaceous earth. The first thing I’d like to discuss is different brands and their pros and cons. E.g. Napa 8822 vs. Moltan OptiSorb vs. Axis, etc. I have been using Napa in the last couple years but never was very happy with the consistently small particle size and lots of fines. This winter I managed to get a hold of a large amount of OptiSorb and am really excited to use it because the paticle size seems pretty perfect. the only real drawbacks with Optisorb I can see so far is that I still don’t end up with much over 1/4" for a drainage layer and it seems slightly more dusty than Napa, but I can deal with rinsing the dust off for $9 per 50 lb bag.

Something I am really interested to hear about is peoples opinions on Optisorb Vs. Axis. Both products are made by the same company EpMinerals, so theyre definitely coming from the same source. Optisorb is marketed as oil absorbent and Axis is marketed as the ‘Horticultural’ grade. Does anyone have experience with both? Is Axis less dusty? Does it have a different particle size profile? I have seen Axis being sold for almost 8 times as expensive per weight compared to my 9 dollar/50lb bags of OptiSorb so if it’s basically the same thing I don’t understand why you would go with Axis, from a financial point of view. Let the soil debate rage!


There is a person on the discussion forum that is selling the Axis product - It is a much better particle with sizes over 1/4".

I also recently purchased a bag of Down To Earth’s Diatomite Rock to check out. I posted some info about it here - It looks very similar to the Axis product.

I use here in Montreal a brand of DE called Qualisorb - which is also coming from EpMinerals and it is probably the Canadian brand name of your Optisorb. I find that the particle size is mostly 1/4 to 1/8 but there is a lot a variability between bags with some full of crushed and dust and other cleaner. Probably also due to how they’re handled through the supply chain up to getting into my hands. I have trees that are in 100% DE, others that are in mixtures of DE and pine bark or coconut shells. I have Acer palmatum, Olea europea, Coprosma kirkii, Pinus banksiana, several types of Juniperus, Larix laracina, Picea, willow… I am happy with it but I don’t really have any controls of having used other soils on the same species. Frankly, I think that if it mets the minimum requirements of drainage, CEC, aeration - things that can easily be manipulated by changing the components and their relative quantities in the mixture as well as carefully adapting watering practices, then anything goes. After all, as discussed in the Naka podcast, he used a soil mix that would have people up in arms, yet had wonderful trees. The key point I think is that you adapt your practices to whatever the mix is that you feel comfortable using.


I noticed that in the first link, the DE is calcined. Would that make it more like turface and other calcined clays as opposed to akadama? Or is it still a good akadama substitute?

@gary1218 Ohh, I had actually glanced at that thread or a similar thread on Bnut where that user was talking about selling DE Coarse, didn’t realize it was Axis! And for some reason that bag design of Down to Earth’s Diatomite rock looks very familiar… trying to think of where i’ve seen it recently…

@nmhansen I’m a little confused about that too. As DE is not clay, and has a completely different structure I don’t think it is an issue. Like Ryan has explained, most clays have a plate-like structure that make them hold water without giving it back and I think Turface falls under that category, whereas Akadama is unique in the clay world as it has a (totally) tubular structure.

I believe what calcined really means is that the product has been fired to some degree. There is a lot of debate, confusing debate at that, on this thread over at Bnut about what calcined actually means when it comes to DE.

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I started using DE here in Australia in 2007. Not understanding the product at all I jumped in and started using it. I found it extremely good for building very fine roots. The company I purchased it from (Maidenwell mines) has since ceased operations. There is another company that mines it in a different location here and doesn’t use the same processes and achieves a different product as the outcome, much softer. It turns into a soft slurry in a relatively short time in the pot, or at least that is my experience with it. When I originally started using the Maidenwell product I heard it had capacity to draw the moisture from curl grubs that exist in the pot. I found that to be true very quickly!

The initial experiments that I did, I used a group of Ficus nerafolia’s, the product showed the plants in DE to be far more vigorous, a healthy colour and appearance to have a better immunity to pests etc. The most difference however is what happened to the roots. The root system was extremely fine and completely filled the container over the same time frame.

I was driving home from work one afternoon and noticed the local council cutting down some Ficus Hillii. I had seen these trees growing there for some time and thought they had pretty good bases so I pulled over and spoke to the guys doing the job and asked if I could take a few stumps home. They said yes (with a very puzzled look) and although I didn’t get the bases I wanted as they had cut them off at ground level and were feeding the trees into a mulcher, I did get a couple that I thought I could take home and least see if DE could work to strike roots with them. They had very little potential for use for anything else so I put them in large nursery cans into 100% Diatomite.
They started to grow foliage very quickly and as time progressed and it was apparent that it wasn’t only stored energy that was used to grow the foliage I figured they must have been growing roots also. After about 6 months and sick of watering these things and having them take up so much room now with considerable foliage mass, I decided to remove them from the pots and take a look. The root system that was produced was extremely fine and originated from the entire circumference of the stumps. These are the pictures taken of the experiment in 2009. I will also attach the Elemental Analysis (if possible) here if anybody is interested in it.






Sorry, cant upload a PDF here but if anyone is interested i am happy to send it to you.


I’ve been using Napa’s #8822 for around four years now, and I’ve had good luck with it. I like the particle size that I usually get after I sift out the dust (between 1/4 and 1/8), and my trees, mostly junipers, like it too. I’ve seen some articles and videos that say DE doesn’t handle freeze/thaw very well, but I haven’t noticed any breakdown of the particles. I’ve repotted some trees after three years, and the DE was still largely intact. The only con that I used to have with DE was the color, but now I top dress everything as Ryan says we should, so that’s no longer a concern. I really just think you can’t go wrong for the price, and it’s like rafi said, you adapt your practices to your mix. Or, like Ryan says, learn to “speak bonsai.”


Hi, I had the chance to sift three bags of Qualisorb calcinated DE in preparation for repotting. I got on average some 55% 1/4-1/8 and 45% 1/8 and smaller (only slightly more of the 1/4-1/8) but the variance was quite high on the three bags (around 50:50, 40:60 and 70:30). I like the colour of this product, when wet it is some dark beige and when dry very pale. The difference in colour between dry and wet is extremely clear. I also see that it is extremely freeze/thaw resistant. Like I said before I don’t have a control with other soils, particularly Chabasai but I am quite happy with DE. It seems that it is slightly more expensive here in Canada than in the US, around 12 USD per 22L bag.

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After reading this thread I went out a bought a bag to try. The Qualisord brand from Canadian Tire. Almost the whole bad was very fine particles. I didn’t measure because they were too small to bother. I want to make this work though as ordering Akadama from Japan isn’t efficient and consistent enough to work for me. I’m going to go buy three bags today from various spots on the pallet and hope I have better luck with the particle sizes. Thanks for opening my eyes to this!

Hey @MrJesseStrong, I think you should try to sift it. Like I said, mine bags contain on average 50% (varying from 40% to 70%) 1/4" to 1/8" (nothing larger than 1/4") and the rest is finer than 1/8", which if I had a 1/16" and would add down to that size as usable soil, would considerably decrease the amount of wasted soil.

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Oh yeah I’m going to be sifting today actually. I figured buying three bags from different locations on the pallet and then sifting to record the results might give me better info on exactly which bags have the larger particles. If I can find out if there’s a specific area on the pallet that consistently produces bags with higher quality particles then I’d make our trips to the store for DE a little easier and a little more productive. I’ll keep you posted once I’ve done this three times from three different stores.

Really, really broad question:

Do we have any more evidence – anecdotal or otherwise – about how well DE works as a replacement for akadama? Are there specific situations in which it does or doesn’t work?


A lot of people use it with great results. I have most of my trees in DE right now. For conifers I’ve been doing 1:1 DE to perlite. They’re doing great. Ive started using more a 2:1 DE to perlite for my deciduous. Though I have some deciduous in 100% DE and they’re growing well too. The DE I use is Optisorb. It has a larger average particle size than the Napa bags I’ve bought. Though I still use Napa for shohins because the smaller particles are great for that use. I have a shohin Spirea in 100% Napa 8822 and it is growing beautifully.

There is a lot to show in the bonsai world that supports DE as a fantastic soil component. Well renowned European Bonsai artists have been using DE for decades. There’s a brand of kitty litter they use over there that is 100% DE. They were widely using DE in Europe for bonsai before it caught on in The USA. Hope that helps!

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I have used both Napa 8822 & Optisorb. They are both exactly the same product in my neck of the woods here in GA. Both very white in color when dry. Same amount of fines, which is quite a bit but I don’t really mind because I use those for cuttings. The particle size is smaller than I would prefer but I can live with it. The Optisorb is $18 a bag and the 8822 is $9 a bag. I would like to try the Axis but until I see others with much improved results, I can’t justify the price versus $9.

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I’m curious about the water retention for DE. I think it takes in about the same amount of water as akadama, but does it hold it for the same amount of time? Does it get drier sooner than aka? Is this even a thing? lol

@vicn1502 Buy some and try it out. Do a little experiment, fill two identical containers with DE and Akadama sifted to the same particle size with nothing planted in them. Water them and then see what dries first. DE holds a lot of water. It holds its weight in water. Meaning wet DE is twice as heavy as dry DE, more or less.

I think I posted this video somewhere before, but someone has already done a lot of the work for us.

Watch for the corrections in the description!


This is amazing BIT of information @el_cheezer thank you :+1:t4:

Hey guys im not sure anyone has mentioned this but american bonsai is a great resource for right sized d.e. . Ive transplanted my japanese maples and some other things in d.e. mixes in grow bag while their prebonsai. I can tell you my experience after this growing season

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