Perlite and beyond: the pros and cons of various drainage and aeration amendments

[heady blunts]

oo another sticky! way to go mad!

 

[TACOE]

'grats on the sticky..
haven't been around much, but i assume there is still interest in Calcined DE as an aeration ammendment.

Now I know this is unrelated and will be deleted if necessary but....

any mushroom growers?
i've been doing some preliminary reading about PF Tek to get started, and as I understand so far, the perlite in the fruiting chamber is just there to "hold" moisture and keep the humidity constant.. cakes seem to just rest on the perlite or even rest on something on the perlite... So it seems perlite is not a substrate at all.

well, as i learned from mad some time ago, perlite holds virtually no water... and apparently it gets the job done for these folks.

now my question is.. if using cakes, would it be a bad idea to use calcined DE to humidify and hold cakes... it wont "over-humidify" will it? and as i recall, the pH was pretty neutral.... any reason you wouldn't want to set a cake on this stuff?

or how about at least a layer on the bottom of either DE or clay floor dri.... something with internal porosity,,, covered with perlite


any opinions greatly appreciated.

 

[h.h.]

http://grow.lot-o-nothin.com/contai...arquest-premium-automotive-oil-absorbant-8033

 

[h.h.]

The size of the aggregate in comparison to air and water molecules would give a certain range of optimum sizes. Clearly the most important aspect. Secondly though comes uniformity in size with in that range where droplets are passed from one piece to the other with no interruptions. Sounds good to me anyway.

 

[mad librettist]

The size of the aggregate in comparison to air and water molecules would give a certain range of optimum sizes. Clearly the most important aspect. Secondly though comes uniformity in size with in that range where droplets are passed from one piece to the other with no interruptions. Sounds good to me anyway.

what we are looking for is a low surface area:volume ratio
the rule is, as a (more or less spherical) particle gets larger, the ratio of its surface area to it's volume goes down. this is the rule that limits the size of the cells in your body

other important properties we are concerned with belong to the water: adhesion (attraction to the particles), and cohesion (attraction to itself)

when surface area is high relative to volume (small particles), more of the water is being held on the surface of the particles and in the spaces between them and the next particle. the water molecules stick to each other which excludes air.

when surface area is low relative to volume, more of the water is being held inside each particle, and at the same time there is much less water held between particles because there is less water on each surface.


if you wet down a pile of coarse calcined DE, and a pile of fines, you can observe just how much more the smaller particles stick to each other. since it's water acting like as the glue between them, we can deduce that the pile of fines has less air porosity than the pile of coarse particles.

The smaller the particles get, the more sticky they are when wet.


and things are a bit more complex than people imagine. for instance, if 95% of your particles are large-ish, and 5% is loose clay, you can't simply multiply the effects of the clay by four to predict the effect of having 20% loose clay. Likewise, adding 1% more drainage component doesn't change your drainage characteristics by 1%.

 

[h.h.]

Until you add soil. The soil fills in the pockets, displacing the air. Moisture adheres to the soil. As the aggregate gets closer to the size of the medium, the pockets, while smaller, are too small for the medium to fill. In a backasswards sort of way, you would get more air.

 

[Bluenote]

CC1

IYou can probably understand why I've become such a devotee of her as a future political star in addition to her taxing role as a reality TV star. I could see her teaming up with former (and part-time) Alaska governor for a presidential run in 2012.

"Mama Grizzly & Jersey Fat Ass"

CC

Egads The Milf And Bimbo " look at me I'm So Bimborific" Party.........


Just the idea makes me want to fart in an elevator with a politician.

 

[mad librettist]

Until you add soil. The soil fills in the pockets, displacing the air. Moisture adheres to the soil. .

you are describing concrete, which is what you get if you screw up badly


like when someone reads about using sharp sand to loosen clay, then goes out to home depot and picks up a bunch of playground sand. mix it up and you have a disaster.

 

[mad librettist]

Unavailable soil water:

Types of water are not available to the plants are
a) Hygroscopic water
b) Fraction of inner capillary
c) Water vapour

Water below the hygroscopic co-efficient is held so tenaciously above 31 atmosphere that is unavailable to plants. The water held between the hygroscopic co- efficient (31 atmosphere) and the wilting point (15 atmospheres) is inner capillary water. Its movement is extremely sluggish and is only difficultly available to plants. Only certain type of plants under arid conditions make its use. So also some bacteria and fungi use the inner capillary water. It includes whole of the hygroscopic water plus a part of inner capillary water being below the wilting point.

Available or Desirably available water:

The range of water between the limits of field capacity and wilting point (co- efficient) is considered as the desirably or available water. The soil moisture between field capacity (1/3 atmosphere) and wilting point (15 atmosphere) is readily available moisture.

Superfluous water:

It includes gravitational water (excess of field capacity). This water is also unavailable to the use of plants because it is lost due to deep percolation. The preference of superfluous water in soil for longer period is harmful to plant growth.

http://www.agriinfo.in/?page=topic&superid=1&topicid=9

 

[h.h.]

Concrete is a mixture of different sized aggregates. The rational for wanting a drainage amendment close size to that of the medium.
I'm not sure of the quote. It sounds like a complicated way of saying the plant will wilt before all the capillary water is extracted. Probably why we don't grow on Mars.
Not yet anyway, Give Newt another tote.

 

[niceeven]

Great thread and it leaves me with a question:

I am curious if oat of wheat chaff would help me achieve similar results as rice hulls ? Any thoughts out there amongst the organic experts?

Thanks in advance,

 

[mad librettist]

my only thought is to ask you to update us on that if you try it.

 

[niceeven]

Thanks for the reply mad librettist.

My suspicion is that it would break down faster than the rice hulls but having said that I will definitely try it as believe in using local materials as much as possible and rice happens to be in very short supply on the Canadien prairies!

I'll keep you posted.

 

[ixnay007]

I can't find much in the way of D. earth here, apart fromt he powdered variety here, they call it fossil flour (farina fossile) and it's used your filtering wine/beer, or other alimentary uses.

Does anyone know if companies like axis have european distributors, I wrote to them, but they never bothered to reply

 

[heady blunts]

I can't find much in the way of D. earth here, apart fromt he powdered variety here, they call it fossil flour (farina fossile) and it's used your filtering wine/beer, or other alimentary uses.

Does anyone know if companies like axis have european distributors, I wrote to them, but they never bothered to reply

i think VG is on your side of the atlantic, and if i remember correctly, he uses a type of clay product similar to DE.

some kind of kitty litter i believe.

 

[mad librettist]

I'm not sure if it's been said here but -

the real benefit from DE or turface (in the 1/4" range) is the dual nature of these particles. In one sense, the calcined chunks behave like sharp sand or builder's sand, but in another sense, they are made of billions of tiny clay or clay-like particles that retain their original properties inside the aggregate.

So you have the texture properties of sharp sand combined with the chemical properties of clay, with the quite improbable result of neither function interfering with the other.


at least that's the idea.

 

[VerdantGreen]

I can't find much in the way of D. earth here, apart fromt he powdered variety here, they call it fossil flour (farina fossile) and it's used your filtering wine/beer, or other alimentary uses.

Does anyone know if companies like axis have european distributors, I wrote to them, but they never bothered to reply

yeah i couldnt buy calcined DE, it is listed in a couple of places as floor dry type stuff but not in stock, or they send you a bag of inferior stuff that turns to paste when it gets wet.

greens horticulture sell seramis which is expensive and actually the same thing as sophisticat pink non clumping cat litter - it is calcined clay or danish molar clay.
http://www.petsathome.com/shop/lightweight-non-clumping-pink-cat-litter-30ltr-by-sophisticat-15257
i think tesco do an own brand type one as well.

VG

 

[przcvctm]

*

 

[moses wellfleet]

has anyone used LECA? it is hydroclay that has been crushed until the particles are roughly the same size as chunky perlite. the nice thing about it: it doesnt breakdown like perlite so you can reuse it. i reclaim it by floating it out of my old soil mix

forgive me if this has been mentioned before i have not had time to go through this whole thread yet!

 

[minds_I]

Hello all,

I am building a raised bed container approx 3'X9'X22"H.

I have to provide soil -soilless fill.

The local provider of "good organic soil" here in the heart of the redwoods wants $140 a yard for his top of the line stuff containing about 25 organic ingrediants such as
blood meal
bone meal
bat guano
chicken compost
mushroom compost
gypsum
perlite
ewc
redwood compost
and mycorizzal(sp) inculatant
and other things not mentioned.

Now I need two yards but refuse to pay almost $300 for two cubic yards.

I can get compost (chicken-aged), blood and bone meal, bat guano, ewc, dolomite.

I can get perlite also but I have a few yards of river gravel (1/2" to 1" dia.).

Can I use this in place of perlite?

If so, what ratio would you recommend?

minds_I