# LECA Comparison Study



## Ray (Nov 30, 2019)

Over on Facebook, someone suggested that there needs to be an updated comparison of available brands of LECA, similar to the one I did about 20 years ago. 

I volunteered to do that if folks will send me samples to test. Here's how this is going to work: I already have Hydroton, so if you have another brand of LECA and are willing:

1) Send me a PM with the brand. If I do not have that one in my array of materials, I will share my shipping address.

2) Get a small, flat rate box from the USPS ($7.90 postage), fill it with NEW, UNWASHED material, and send it to me. (To compensate you for that expense, I'll send you a coupon code that will give you $7.90 off the price of a bottle of KelpMax.)

3) Once I have received the samples, I'll run a variety of tests and will publish my results. 

Right off the top, I thought I'd do the following:

> TDS of soak water - will tell us how important precleaning is.
> Bulk Density - relates to stability,
> Wicking ability
> Free air space
> Absorption

Any other ideas?


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## orchid527 (Nov 30, 2019)

Ray

Friability would be useful as an indicator of physical stability. Perhaps pouring back and forth between containers, looking for newly created fines. You could also place weights on them until they crush or fracture. I have used only Hydroton, so I don't really know what the others are like. Mike H


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## abax (Nov 30, 2019)

I have Hydroton too. No help.


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## Ray (Dec 1, 2019)

orchid527 said:


> Ray
> 
> Friability would be useful as an indicator of physical stability. Perhaps pouring back and forth between containers, looking for newly created fines. You could also place weights on them until they crush or fracture. I have used only Hydroton, so I don't really know what the others are like. Mike H


Interesting thought, Mike. I'm not so sure about what meaning we'd get from such an evaluation. Mechanical integrity of ceramic bodies depends upon the chemistry and the firing, and I really doubt the control is anywhere near the rigor that other ceramic materials see.

Let's not forget that LECA is manufactured to be a "crack stopper" in concrete, so it's ability to break and dissipate the energy is what it's designed for.

I also question how important that is to plant culture - if there is damage, it is far more likely to occur in transit than in a pot. I'm not looking to just do more testing, but will if it has value.


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## NYEric (Dec 2, 2019)

Can't even get this from hydroponic stores in NYC. They say big Pharma companies are buying it up.


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