Expanded shale grow beds

[David W. Russell]

Hello all.  I have opened this forum to learn about the long term use of Expanded Shale.  I invited everyone to add to this "bed" of knowledge.

 

I have been talking to the following person: 

Debbie Stringer                                         [e-mail]

Sales/Technical Representative
Horticulture & Environmental Products
Stalite PermaTill, North Carolina
cell: 704-906-5953
www.permatill.com

www.stalite.com

 

From the information she sent me, her own lab results showed that the ph of washed shale started at a high of 9.42, then spiked up to 10.88 and then settled down to a 7.90 within a 14 day period.  Now this was a sample put into DI water.  It does not show a replacement or changing of the water.

From her letter to me I got the following: 

"It is $100.62 per ton which is $73.45 per cuyd. The weight is approx 1400 lbs per cuyd.

We do not supply the trucks so you will have to pick it up."

So, a few questions pop up?  If you are using a tote based system, how many lbs. of this do I need to run an 18' bed?  Will the ph lower after a few months?

Are there differnt types of expanded shale?  Does one from the Midwest differ from one from the East coast??

At www.expandedshale.com, they write:  Expanded Shale is a silicon-based material that is pH neutral.  The heating process in the kiln creates calcium and magnesium oxides on the surface of the material which can generate an alkaline pH.  Simply washing the material prior to use will remove the oxidized dust.  A report by Texas A&M University Research and Extension Center pubished an article in "HortTechnology" in October 2002 about the chemical properties of Expanded Shale and the effects it would have on clay soils as an additive.  They state that "[Expanded Shale] will not measurably affect the pH of neutral or calcareous soils".

 

So i invite any and all discussion on this subject including size requirements.  I'm told 3/4 would be the best.

 

Who has used this long term?????

Thank you,

Big David

 

 

 

[Jeff Iverson]

I am interested to hear how ES compares to hydroton.

[Chris Schup]

I am also interested to know.

[RW]

We've been discussing this in the Texas aquaponics group a bit.  Here's a link. http://aquaponicscommunity.com/group/texas/forum/topics/expanded-sh...

 

So far the exapnded shale I've found in my area effects ph enough to make me pass on it for now. Based on my not too scientific tests. Also, it's difficult for me to get the right size at the right quantity locally. I've decided to do red lava rock on the bottom third of my grow beds and hydroton on the top 2 thirds.

[George]

http://www.expandedshale.com/Products/Shale/ExpandedShale.aspx

Jeff Iverson said:

I am interested to hear how ES compares to hydroton.

[TCLynx]

hay David, seeing as you are down in Miami FL and can get the 3/4" Stalite (I believe this is actually espanded slate rather than expanded shale) I would say it is probably worth it to you.  I have washed some of the 1/2" stuff and it is reasonable so the 3/4" would probably be great.

To figure out how much you need, just do some math to figure out the cubic feet you need so you can figure out the cubic yards and do the math to figure out the aprox tonnage you need.

Keep in mind you need a truck that you are not afraid to drive into a distrobution yard and let one of their front end loaders dump rocks into it or you need to find some one with a dump trailer or dump truck that can get it and deliver it to you.

As to the pH.  I would swish the material in some bins of water to remove as much of the oxide dust as you can.  Then I would have the grow bed filled with water  but divert the drain temporarily so you can do a little acid wash on the media before hooking it up to the system so it won't be spiking the system too high to begin with.  Then you can give the media an extra rinse in the bed before letting it drain and hooking it into the main system.

Now I can't say much about using Stalite long term though since I haven't yet.  It is much easier to wash than the 1/2" brown river rock since it is so much lighter but the total cost is probably about the same.

[David W. Russell]

TCLynx, you got the terms correct, and pehaps I am using the wrong definitions.  Stalite is slate.  Is slate that much different then shale??    The term " a little acid wash" - are we talking 4 cups of pool acid per bed?

[Rob Torcellini]

I can give a few tips on this subject.  First of all, as a disclaimer, I run Bigelow Brook Farm, which sells expanded shale and owns the expandedshale.com website.  ;-)

I have samples of shale from various quarries from around the US.  I was actually surprised to find that the shale is very different from each quarry.  From one place, the was very rounded and had very few fissures and pockets and was almost like river rock.  The quarry where we buy our shale from it is very porous and randomly shaped.

I also practice what I preach and grow with the expanded shale.  I do have some growbeds with crushed granite and some with shale.  Since they are in the same circulation system, I have no scientific proof that the shale has a better biofiltration over regular stone.  However, it is far easier to work with.  The slightly rounded corners is easy on the hands, and when you pull plants out, the shale gives way easier so you can get more of the roots out.  My beds are still filled with red wigglers too!

If you buy regular shale from the quarry, it is typically filled with a LOT of fines so you are paying for a lot of dust.  You will have to rinse it or the pH will go crazy high on you.  The material we sell has be double screened so the majority of the fines are gone and there is just some dust left on the stone.  My system is around 50% shale and the water pH stays at around 7.5.  That's what the water was before I added the shale so it hasn't changed at all.  Typically pH swings are not from the shale, but from some other factor in the system. 

As a sales pitch, we have 1 liter sample packs if you want to play with it.  You can also get 25 or 40 liter boxes, or pallitezed shale from TCLynx (http://www.aquaponiclynx.com/products/expanded-shale-rocks-in-a-box) or from The Aquaponic Source (http://www.theaquaponicstore.com/Expanded-Shale-Grow-Media-s/105.htm).

Hope this helps! 

[TCLynx]

I can say that I've handled a few different products.  The Stuff Rob has (The expanded shale that is twice screened) is nice and if you want a small quantity shipped to you, I would recommend it.  Unfortunately, unless you live up in New England, it gets costly to freight the bulk stuff around.  But anyone who lives anywhere near him, should get his stuff.

If you are thinking of getting any of the other Expanded Shale or Slate products.  You want to get a sample of it or make arrangements to go to the distrobution yard and get a sample.  The amount of fines in the stuff is going to vary by pile and where it is scooped from the pile too.

I have seen Expanded shale that some one got locally in Florida as well and though it was listed as 1/2" I think it was actually 1/2" and smaller.  The Expanded Slate I'm testing out they had 3/8" and 1/2" so the 1/2" stuff has far fewer fines in it since the fines probably mostly got screened into the 3/8" pile.

As to the acid wash, I used a cup or so of muratic acid in 200 gallons of water with the Stalite.  (mainly I added acid a few times to the water as we were filling the bed since I wanted to make sure I got it down below 7.6 before draining and hooking up to the rest of the system.

I am also unable to vouch for the performance of the Stalite relative to other stuff since it is in a system with other media and not being tested in isolation.  Give me another year or so and I'll be able to report better on the longer term pH properties.

[David W. Russell]

Rob,

I met you at the conference and you are the person that educated me as to the value of your product. (Many Thanks - I have your sample box on my desk.)  I am now starting a tote system and must figure out the amount of product that I will need to fill the tote to a depth of 18".  Im taking my time, as I don't have alot of money and belive that education is more important then moving quickly.  Thanks for you reply.  Hope to see you in Denver.

Rob Torcellini said:

I can give a few tips on this subject.  First of all, as a disclaimer, I run Bigelow Brook Farm, which sells expanded shale and owns the expandedshale.com website.  ;-)

I have samples of shale from various quarries from around the US.  I was actually surprised to find that the shale is very different from each quarry.  From one place, the was very rounded and had very few fissures and pockets and was almost like river rock.  The quarry where we buy our shale from it is very porous and randomly shaped.

I also practice what I preach and grow with the expanded shale.  I do have some growbeds with crushed granite and some with shale.  Since they are in the same circulation system, I have no scientific proof that the shale has a better biofiltration over regular stone.  However, it is far easier to work with.  The slightly rounded corners is easy on the hands, and when you pull plants out, the shale gives way easier so you can get more of the roots out.  My beds are still filled with red wigglers too!

If you buy regular shale from the quarry, it is typically filled with a LOT of fines so you are paying for a lot of dust.  You will have to rinse it or the pH will go crazy high on you.  The material we sell has be double screened so the majority of the fines are gone and there is just some dust left on the stone.  My system is around 50% shale and the water pH stays at around 7.5.  That's what the water was before I added the shale so it hasn't changed at all.  Typically pH swings are not from the shale, but from some other factor in the system. 

As a sales pitch, we have 1 liter sample packs if you want to play with it.  You can also get 25 or 40 liter boxes, or pallitezed shale from TCLynx (http://www.aquaponiclynx.com/products/expanded-shale-rocks-in-a-box) or from The Aquaponic Source (http://www.theaquaponicstore.com/Expanded-Shale-Grow-Media-s/105.htm).

Hope this helps! 

[Rob Torcellini]

TC is right that it can get a bit expensive to ship.  I'm finding that some of my sales are to apartment dwellers that just need a small amount shipped to them.  The majority of my sales are to the locals.  It's quite entertaining watching people put several hundred pounds of shale in their trunk....their front wheels are almost off the ground.  ;-)   I've even loaded up cars where they put it in the passenger seats to distribute the weight. 

when I get the dome greenhouse up and running, it will have shale in all the media beds...sort of a no-brainer since I have a huge pile of the stuff!

[TCLynx]

LOL.

[George]

The subject line indicates a shale discussion but I believe the company you're talking to sells expanded slate. 

Expanded shale grow beds

• Posted by David W. Russell on December 19, 2011 at 1:39pm in Media Topics
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Hello all.  I have opened this forum to learn about the long term use of Expanded Shale.  I invited everyone to add to this "bed" of knowledge.

 

I have been talking to the following person: 

Debbie Stringer                                         [e-mail]

Sales/Technical Representative
Horticulture & Environmental Products
Stalite PermaTill, North Carolina
cell: 704-906-5953