What are the LECA or other S/H media options available, anyway??

[rosemadder]

Even at some large hydroponics stores that I have visited, and on various websites, I keep finding absolutely generic "clay pebbles". Usually the store will have only one type, and the bag is really bland with no indication what's actually IN it or where it came from. This is making it really hard to figure out what varieties are actually out there!

I'm not interested in speculating or debating on which ones are "best" or whatever, I just want to know what the options ARE, and maybe some of their very basic properties.

Shall we make a list? Alphamabetical, even.


LECA AND OTHER INERT PEBBLE TYPES:

• Aliflor
  LECA.
  Irregular.
  
  
• Calcined clay
  Clay that is fired, porous, and lightweight
  Not made in the same process as LECA
  Irregular
  Sinks
  Size 1/8"-1/4" chips
  High CEC
  Wicks well
  Available in dark gray, red, brown
  Brand names such as: Turface, SoilMaster Select, AquariumPlants.com's Own, AquaDurt
  Available at tractor supply, possibly home depot etc.
  Also sold as floor dry/oil absorber at auto parts stores.
  Resembles but NOT the same as cat litter, which is fired at a lower temperature and disintegrates when wet.
  
  
• Growstones
  Recycled glass.
  Irregular shape.
  Floats, very light
  Soda-lime glass tends to be alkaline and raise pH
  
  
• Hydrocorn (aka Hydro Korrels)
  LECA
  Irregular.
  Floats, mostly.
  
  
• Hydropebbles
  LECA
  Round.
  Similar to hydroton, used as a replacement by some distributers.
  
  
• Hydrolite
  Silica.
  Sinks.
  has some CEC?
  
  
• Hydroton
  LECA.
  Round.
  Two sizes.
  No longer manufactured, some stock still available.
  
  
• Lava rock
  Very generic term that spans a huge range of volcanic deposits. Usually refers to cinders.
  Can be rather heavy and abrasive.
  Wicking low to nonexistent
  (this one kinda bugs me, because I'm from a volcanic area and to me, 'lava rock' specifically refers to solid rocks from actual lava flows. Cinder is a bubbly material that was spat out high into the air, like pumice but heavier.)
  
  
  
• Leca® UK Lightweight Aggregate
  Not much info available on this. It mainly seems to be for big-scale industrial applications and may be rebranded for retail.
  
  
• PrimeAgra ("new type")
  LECA
  Irregular
  Available only from firstrays?
  
  
• PrimeAgra ("old type")
  LECA
  Irregular
  No longer manufactured.
  Any stock available? Dunno.
  
• Root Royale Hydro Clay
  LECA
  Irregular, rough
  Floats
  Lighter than Hydroton. Slightly smaller. Darker brown.
  Fragile, breaks up into sharp chunks and annoying small fragments.
  
  
• Sunleaves rock
  Heavy expanded shale
  Irregular
  Reported to wick more than hydroton
  
  
• Terracotta
  From broken pot chunks to water-holding sculptures.
  Wide range of porosity.
  
  
• ViaStone
  Not much info on this, it's probably something else rebranded.
  

Other names I've run into but I can't find much info on:

Grorox

Geolite

Lecastone

Some of these may just be alternate names for products I've already listed.

Problem is, so many people out there use the brand names as if they're the official terms for leca in general.

OTHER HYDROPONIC MEDIA:

• Coconut husk
  Organic, breaks down relatively slowly
  Available in dust, fiber, and croutons
  
  
• Ecoweb
  Plastic spongey stuff
  Does not wick much
  Mentioned on Firstrays, but does not seem to be available yet?
  
  
• Epiweb
  Plastic spongey stuff
  Does not wick much
  From the swedish company Dusk Tropic. Have only found it for sale in english on dartfrog.co.uk and folius.net
  
  
• Hygrolon
  Inert polymer cloth material
  Wicks effectively (site says it pulls water up to 32cm)
  From the same company as Epiweb
  
  
• Gorilla Hair
  Redwood bark fibers
  Organic, breaks down relatively slowly
  
  
• Rockwool
  spongey mineral stuff
  Wicks very well
  Not always re-usable
  Be careful when handling, as with fiberglass insulation etc.
  
  
• Swamp Stick
  Hollow ceramic stick-shaped mounts
  May be getting discontinued?
  

Okay, what have I missed? Anybody out there with additional items or information on these? I'll update the list as I find more stuff.

[vjo]

I didn't know that coco husks would be considered hydroponic.I was under the impression that it had to be an inert material. Wouldn't bark be useable then too?...Jean

[rosemadder]

Originally Posted by vjo

I didn't know that coco husks would be considered hydroponic.I was under the impression that it had to be an inert material. Wouldn't bark be useable then too?...Jean

Maybe. Not sure. I know I definitely keep running into coco husk at hydroponics places. Maybe it breaks down slower in water than bark does? I'd be interested to find out.

[Ray]

Rose, I think that the reason you primarily see generic brands of LECA in shops is because they are focused on active hydroponics for terrestrial plants (pot - see attached - from the DEA website), in which the stuff is used primarily as mechanical support. If you are continuously (or periodically on a timer) flooding the medium with nutrient solution, properties like nutrient storage and release, and capillarity are quite unimportant.

CHC would be effective in that application, as it would last long enough to harvest the leaves, then throw the root ball away.

I will add that I still sell PrimeAgra.

[DTEguy]

Sunleaves rock
Heavy expanded shale
Irregular
Reported to wick better than hydroton and has been around in the weed community

Hygrolon
Innert polymer cloth material
Cut into small pieces and will wick from bottom as shown by Magnus:

http://www.orchidboard.com/community...ppy-roots.html

sold by: Hygrolon › Folius Enterprises LLC

[DTEguy]

I think Epiweb and Ecoweb are not suitable for S/H because they do not wick.

I tested growstones (without any orchid in it); it's super light/unstable and raises the pH of the fertilizer solution.

[rosemadder]

Originally Posted by Ray

Rose, I think that the reason you primarily see generic brands of LECA in shops is because they are focused on active hydroponics for terrestrial plants (pot - see attached - from the DEA website), in which the stuff is used primarily as mechanical support. If you are continuously (or periodically on a timer) flooding the medium with nutrient solution, properties like nutrient storage and release, and capillarity are quite unimportant.

Good point! Thanks for chiming in, Ray.

I also believe that most LECA probably comes from just a few really large manufacturers that do not sell retail, and various companies re-brand the stuff with whatever name they want to put on it. I think a lot of it comes from somewhere in Europe, and Taiwan.

Similarly, for my planted aquarium I was doing a lot of research on substrates. The stuff from aquarium supplies tends to be pretty damn expensive-- but again, a lot of it is just re-branded industrial materials, like coal slag (waste byproduct from coal burning power plants!) and calcined clay (used for stuff like baseball diamonds). Calcined clay is a little similar to LECA actually, it's fired clay that is quite lightweight and porous. It isn't spun or coated, and usually comes in little chips maybe 1/8"-1/4". If it was bigger I'd want to test it for S/H, but I bet it doesn't wick well. It is sold under probably dozens of other brand names (Soilmaster Select, Aquariumplants' Own etc) but there are only two, maybe three manufacturers-- so only just a couple actual varieties! It proved to be too lightweight for my aquarium. The fish can knock it around easily and uproot the plants all the time.

That was a bit of a tangent I suppose-- anyway!

Originally Posted by DTEguy

I tested growstones (without any orchid in it); it's super light/unstable and raises the pH of the fertilizer solution.

In my research, I came across a thread somewhere, where someone (might have been Ray, don't recall) was explaining that soda-lime glass-- that is, ordinary glass such as bottles are made of-- does tend to be rather alkaline. Lime and all.

I'm curious, did the growstones float?

[DTEguy]

Yes, the growstones float easily, easier than LECA.

Btw, in order to minimize disturbance in the pot, I use a large watering can to flush my hydrotons--instead of a strong pressure stream from the faucet. That way, I can also flush the top layer without raising the water line to the very top and risk floating everything.

[Discus]

If you can get small samples (a cup full would do it), you could probably repeat Ray's experiments in wicking (which are covered somewhere on his website); you should then probably also investigate other properties like how "floaty" they are, and if they have any effect on pH and so on. Once you find one or two that seem OK, you can then try them out and see what works.

Or you can see how PrimeAgra works, which I imagine Ray has spent tons of time investigating as the best available substrate...

Hydroton does not wick very well at all in my experience, but it's the only LECA I can get in this country.

[rosemadder]

Originally Posted by Discus

If you can get small samples (a cup full would do it), you could probably repeat Ray's experiments in wicking (which are covered somewhere on his website); you should then probably also investigate other properties like how "floaty" they are, and if they have any effect on pH and so on.

That would be AWESOME. I loves me some science experiments! But I'm not sure how to come by individual cups of products that are usually sold in gigantic bags!

Again, I'm not really looking for what's "best" here. Different materials are different, and could be suited for different things or particular needs for different plants and different people. I'm just looking for what's available and what their overall traits are, then it's easier for people to figure out what might work best for their specific applications.