Dyna-Rok ll and Diatomaceous earth

[otis 226]

I've seen several posts here that mention Dyna-Rok ll as a component or a complete media for growing certain orchids. While I don't have extensive experience with orchid culture at all. I have been involved in Bonsai growing for over 35 years. I am not familiar with the product Dyna-Rok, but know it is composed of diatomite, or diatomaceous earth. Basically microscopic fauna with a silica shell that over time have formed huge deposits around the world. I just wanted to relate that NAPA auto parts carries a product called NAPA 'Floor-Dri' or 'Oil-Dry' (part # 8822), which is composed of 100% diatoms. It is usually used to cover oil stains in automotive shops, since it has such an absorbent property to it, (supposedly can absorb 150x its weight in liquids). Many bonsai growers use it as a component in their potting mixes, which must be very porous and quick drying from most of the trees grown. I've experimented with it a bit and found that flower seeds sown in it will germinate fairly quickly and the sharp edges of the media, doesn't seem to harm the tender roots of the these seedlings. I've started to use it sparingly in some of my potting mixes, but thought it might be a good alternative to Dyna-Rok ll. A 22 quart bag cost me about 6.99 at a local NAPA store. I have no idea what Dyna-Rok costs but I'd imagine a good bit more than this. The size of the NAPA product is comparable to most perlite I've seen. It is quite dusty out of the bag, (I would wear a mask when handling it, as this is a silicone product, and rinse it well several times before use). I understand that the run off from these rinses can be used as an insecticide spray that kills soft bodied insects via mechanical means, but I haven't tried this as yet.

[Filb]

Thanks for this. I'd never looked into diatomaceous earth as a medium.
It has some interesting properties!

I wonder how sustainable the harvest of it is though.

[Ron]

called NAPA 'Floor-Dri' or 'Oil-Dry' (part # 8822), which is composed of 100% diatoms.

There are several diatomite, or diatomaceous earth products available.
In Australia we have been warned of using some of the products.
The one that come from Maidenwell in Queensland Australia is a fresh water base product.
Some I believe are sal****er ( saltier) based products and contain a fair amount of salt content.

NAPA 'Floor-Dri' or 'Oil-Dry' (part # 8822), which is composed of 100% diatoms.

I have never hear of this product in Australia but as long as it is freshwater based should be OK

[otis 226]

That's true, Ron. This is a fresh water based product, I believe. As I said I've germinated several trays of annual flower seeds in it just to see how that would work, and it did fine, but does dry out quicker then most 'normal' seedling mixes. In the UK, they have a very similar product that is marketed as cat litter,(can't remember the name) but it is also 100% diatomaceous earth, and bonsai enthusiasts there speak highly of it. I don't think I'd ever use it for orchids straight, but it might make a good component. I've got one Phal currently in a mix with some, along with coco husk, charcoal and LECA pellets and after 5 weeks its putting out a new leaf. But I'm new enough at this that I love to experiment. Anyone interested in the article, just look up 'cat litter use as bonsai soil' and you should come across it.
Cheers,
Tony

[otis 226]

Originally Posted by Filb

I wonder how sustainable the harvest of it is though.

Flib,
That's a good question. From what I've been told it's as common as sand, but then, as Ron points out there are both sal****er and freshwater varieties and I don't know if any amount of rinsing would make the sal****er kind okay for our use.

[Ray]

I doubt that salt- or fresh water sources make much of a difference as far an introducing salt to the medium, as sodium chloride is simply SO soluble in water it will wash out easily from the silica structure.

I doubt the NAPA stuff will be of much use to orchid growers, as it is too fine of a product. Diatomite (As Dyna-Rok II) is available in several size grades, but even the finest is several times larger than the NAPA material.

[otis 226]

Okay Ray, as I've never seen the Dyna-Rok product I can't stay, but if the fine is more coarse than the NAPA product, that would mean its more coarse than perlite, which is comparable to aquarium gravel, at least.

[NewGrower]

That is pretty cool! I like growing my orchids in drier mediums because I am an "overwaterer" ha ha!

Thanks for the info, I definitely will look more into this

[Ray]

Originally Posted by otis 226

Okay Ray, as I've never seen the Dyna-Rok product I can't stay, but if the fine is more coarse than the NAPA product, that would mean its more coarse than perlite, which is comparable to aquarium gravel, at least.

I agree.

"Horticulture Grade" (#1) perlite is usually no more than 5mm in diameter. "Fine" grades in orchid media, whether they are bark, CHC, diatomite, or LECA, are more on the order of 6-10mm, but size is not the only factor that can affect performance.

The water-holding capacity, especially "bridging" water is affected not only by size, but particle size distribution, as well, and that is far more critical to orchid growing than it is to bonsai or other culture of terrestrials, and I'm quite sure that both perlite and the NAPA diatomite have a wide range of sizes.

If you have a mixture of particle sizes, the smaller ones fit inside the voids between the larger ones, increasing the packing density and reducing the size of the open spaces. If those spaces are small enough, surface tension can hold water in them, completely blocking air flow to the root system. As the particle size becomes more uniform and larger, those spaces become large enough that surface tension is insufficient to hold water in the entire void, allowing the roots to breathe easier.

[otis 226]

Originally Posted by Ray

If you have a mixture of particle sizes, the smaller ones fit inside the voids between the larger ones, increasing the packing density and reducing the size of the open spaces. If those spaces are small enough, surface tension can hold water in them, completely blocking air flow to the root system. As the particle size becomes more uniform and larger, those spaces become large enough that surface tension is insufficient to hold water in the entire void, allowing the roots to breathe easier.

Totally correct. That is why bonsai soils are sifted and the fines are removed before they are mixed for use. It is essential that the media does not compact between repottings,which for some evergreen species can be 3-5 years.

My original intention was to show a possible cost effective alternative to Dyna-Rok ll in an orchid mix. I never meant to advance the idea of using only Diatomaceous earth as an orchid media, just one component. It absorbs many times its weight of water and it does driy out well.
We all are aware that the way we grow our orchids, with the possible exception of mounts is completly unnatural and its a credit to the hardiness of these plants that they respond as well as they do, many times indoors, without sufficient light and crammed into pots for our convienience.

I should have added these pics with my first post, but I've been busy reading about orchids, (it helps keep me from buying orchids constantly )

I hope the comparisons prove useful to someone

[otis 226]

I should have added these pics, but guess they didn't upload the first time around...

[Brooke]

I also used to do bonsai and my very first orchids were potted in pine bark fines, sifted, with small LECA added to it. It was the same percentage I used for my trees and tropicals. They grew great in this mix because I understood the watering procedures with that mix.

Otis have you ever tried the pond growing media available from a big box store. It is LECA and I still use it for some of my 'chids. I knew about the NAPA stuff but it was easier for me to get the pond media.

Brooke

[otis 226]

Originally Posted by Brooke

Otis have you ever tried the pond growing media available from a big box store. It is LECA and I still use it for some of my 'chids. I knew about the NAPA stuff but it was easier for me to get the pond media.

Brooke

No Brooke, I've never seen it, but I will be on the lookout my next trip to Lowes or HD. I'd certainly love giving it a try. You can't have too many potiential components to experiment with. Appreciate the tip

[Brooke]

Otis I used the LECA on my "finished" trees, not that they are ever finished, but I used turkey grit which is granite chips on grow out projects. If I remember correctly I don't think people along the coasts could get granite turkey/chicken grit.

Brooke

[Ray]

Interesting, Brooke. The poultry grit I have seen is crushed oyster shells.

[otis 226]

Brooke,
I've used poultry grit when we lived up in OH. Haven't really looked for it down here. I sometimes get a bag of pool filter sand and that works for a bonsai component as well.

Oh, and the only really 'finished' bonsai are the dead ones. I've finished lots in my time

[Brooke]

Crushed oyster shells change the PH or something to the potting mix so it cannot be used. Usually the coastal areas can only get the crushed shells but here in the midwest, the granite is available. A 50# bag of turkey grit costs $5. I still use it and the pine bark fines for container growing outside in the garden. Fast draining but moisture retentive and you grow great hosta in whiskey barrels.

Otis the chicken grit feed is the same size of the pool filter sand. I gave away all of my bonsai when the orchid collection grew. I had some trees growing out and ended up planting them in the field You can't let a good tree go to waste!

Brooke

[otis 226]

Originally Posted by Brooke

I had some trees growing out and ended up planting them in the field You can't let a good tree go to waste!

Brooke

Yep, done that both ways, (pot to field and field to pot!)

I'm always lookin' for ways to economize with supplies. Leaves more disposable income for the plants.

[c321m2s]

Hi from oz.Any way growing in Diatomaceous earth is the best thing you will ever do.I grow bonsai in it 100% pure .but it has to be bigger grade in size. As its inert . and never changes in PH .but there is a very important trick to it.first water every day and make sure the whole the whole plant from top to bottom gets wet.You can never over water as it just drains out the bottom.But you must understand that you also have to feed alot . every 12 days or so .Dont worry about the salts from organic plant food building up as the next time you water it washes out .Which should be every day so you can feed more if the feed says 20 mils use 40 mils believe me it does no harm as long as you water alot. Its a combination that works real good this is no secret .look up Walter pall and listen to him talk about modern Substrate follow the parts on Youtube as there are a few parts 2 on substrate and i think 1 on feeding .you will be amazed .the man is the mad scientist of the bonsai world . this is not my idea .and i think even he learned it from someone. All that matters is it works like mad.

[Ray]

Originally Posted by c321m2s

Hi from oz.Any way growing in Diatomaceous earth is the best thing you will ever do.I grow bonsai in it 100% pure .but it has to be bigger grade in size. As its inert . and never changes in PH .but there is a very important trick to it.first water every day and make sure the whole the whole plant from top to bottom gets wet.You can never over water as it just drains out the bottom.But you must understand that you also have to feed alot . every 12 days or so .Dont worry about the salts from organic plant food building up as the next time you water it washes out .Which should be every day so you can feed more if the feed says 20 mils use 40 mils believe me it does no harm as long as you water alot. Its a combination that works real good this is no secret .look up Walter pall and listen to him talk about modern Substrate follow the parts on Youtube as there are a few parts 2 on substrate and i think 1 on feeding .you will be amazed .the man is the mad scientist of the bonsai world . this is not my idea .and i think even he learned it from someone. All that matters is it works like mad.

Dr. Yin-Tung Wang published a brief article in the AOS Orchids magazine a couple of years back that showed that the Maidenwell Diatomite (formerly sold under that name by Diatomite USA and also as Dyna-Rok II) did, indeed, build up salts pretty readily, and fairly irreversibly.

I think part of that is due to the particle size difference of that used for orchids and that for bonsai - the smaller "bonsai size" has a greater surface-to-volume ratio, so can be leached easier.

[otis 226]

I find it a good additive for bonsai and some, select 'chids. I wouldn't use it 100%, as it wouldn't work in my conditions... dries out too quickly and completely.
Thanks Ray, for your input, as always. You too, oz.
Tony