Alternate or recycle media

[Larry Poe]

I am putting together a new system that will be visited by a few local public schools, including 1 or 2 colleges. one of those is a 2 year school that draws a student body from all over the world, including a large 3rd world population.

one thing I was asked was if I would include at least some  alternate/recycled media beds. I am going to take that a little farther and use as much recycle material as possible throughout the system. mostly stuff we all use already like barrels, IBC, ect.

the idea was for the students to be able to set up cheap systems in there home countries.

I would like some input on different types of media everyone has tried. what worked and what didn't. Things like charcoal, bottle caps, crushed bricks, ect. anything that can be made at home (like the charcoal) or saved from the dump (bricks, bottle caps, and the like).

yes I will use some river rock/creek gravel as well ( those are native in a lot of places), but the idea

here is cheap setups that can feed people in places were food is short and the whole "green" thing too.

I am going to set up some beds with each and maybe some layered ones as well. some with constant flow and some with flood and drain.

[Randal Duren]

I like the charcoal (biochar) idea. This can easily be locally sourced, it is light weight, absorbent, porous, has excellent ion exchange, etc. It has not been exhaustively tested either in hydroponics or aquaponics, although some research is out there. I am giving this a try in my new system with a hybrid flood/drain media bed setup in which I have a wicking bed over gravel. Some info in New Member Introductions.

The attached photos demonstrate the setup. The grow bed is 1/2 a IBC tote with a bell syphon. The gravel is about 7" deep. Media filled (80% biochar/20% vermicompost) grow bags (6 gal capacity) rest on the gravel. The bed floods to about 13". Note the water mark on the grow bags. Photo taken at end of drain cycle. The media in the grow bag remains dry on the surface. I dig down (2-3") to moisture to plant seeds and then overhead water until seedlings emerge.  

[Larry Poe]

that bag idea is pretty cool.

I am really looking forward to the charcoal idea myself too. I know of a few systems that use or have used it and about the only complaint I have heard is of "fuzzies" at the top layers after awhile. personally I have wondered if that isn't potassium nitrate aka saltpeter they are seeing but IDK. It seems ideal in the weight issue arena.

so far I know of at least 3 media types I will for sure include. charcoal, crushed bricks, and bottle caps. just looking for some more ideas and anything else someone else has had luck with I haven't thought of, or things they used that didn't work out so well so I can avoid repeating the mistake.

I also haven't seen much about layered media. say bottle caps with a few inches of charcoal or crushed brick..........river rock, ect on top.  something else I am looking forward to trying unless someone else has and it was a complete flop lol.

[Jonathan Kadish NYC AA Chair]

You could talk to any potteries or schools with pottery studios in the area and ask them if they have any bisque shards they can save for you. Broken up and tumbled to break the edges this material is essentially hydroton without the air bubbles. It absorbs water and releases it slowly.

[Larry Poe]

we have a local plant that makes ceramic toilets, urinals, and the like. there is a MOUNTAIN of castoffs and broken units behind it. a lot of it is  unglazed because it never made it that far before it was rejected,  and I can haul it away by the pickup load up to semi load if I want. 

[Jonathan Kadish NYC AA Chair]

That might work, but you need to make sure it has not been fired past 1800 degrees, after that the clay starts to vitrify and become impermeable to water. I would think they once fire to 2350° to save money on fuel skipping the bisque stage.

[Larry Poe]

so far I have just been making bio-charcoal and crushing old ( as in back when bricks were handmade on site and came in 3 grades depending on rather they were the inside, outside, or middle of the temporary oven stacks)  bricks.

there is no such thing as a pottery school or studios around here, but my pond is the " clay mine" of a brick factory that used to be here in the mid to late 1800s. my house is made from bricks that came from that same pit. in the 25yrs I have lived here I have found and stacked up hundreds  between the pond, pasture and house, and a lot of them were broken.

[George]

You can screen the charcoal through hardware cloth to get the desired size.  For example, screen first through 1/2 and then again through 1/4 to remove fines - fines could be used in a soil garden.  good luck

[Larry Poe]

thanks George.  that's where all the ash from my wood stove goes, the garden, and I have a 1/4in hardware cloth "filter" I dump it through already.

I also add a little here and there to the compost bins, and when I start tobacco seeds I mix them with ash and then sprinkle that over the starter beds. helps spread them out (they are TINY) and gives them a boost (tobacco likes a lot of nitrogen and potassium)

[Jonathan Kadish NYC AA Chair]

THE OLD SCHOOL WAY: If you have a lot of clay and a supply of sawdust, dry leaves, twigs, brush and wood  you could 1) mix the sawdust into the clay 2) make the clay balls or cut up coils into beads and dry them in the sun 3) make a burn pit out of your bricks 4) Layer the burnable material and your clay balls and light it up. Your fire pit should reach 1500° to 1800° which will be enough to burn off the sawdust in the clay and transform the clay into media. Humans have been doing this for 25000 years+

I have made them in my wood stove, but if it gets too hot too fast the water in the clay can explode

[Larry Poe]

jonathan,

that is close to the method used when bricks were made here on my place in the late 1800s. clay was mixed with sand or finely crushed reject brick, then dried in the sun. once it had dried, they stacked them into temporary ovens 3 bricks thick (narrow thickness) and built a fire inside the "oven". once it was going good they would close the front and draft and let the brick "cook.

once it was done there was 3 grades of brick. the inside closest to the fire (and cooked the hottest) the middle, and the outside bricks (farthest from the fire and one side totally exposed during the process).

in construction the outside (3rd grade) bricks were used for the inside face of the walls. the inside (1st grade) bricks used on the outside face of the walls and most severe weather facing sides. the middle (2nd grade) bricks were used as fillers and on less weathered outside faces (like the south and east in my area for instance)

my house is built that way and predates 1865 (there are no records in my county before that as the courthouse was burned by federal forces and Kansas jayhawkers during the civil war, so we don't know the exact building date)

when you look at the 3 grades of brick laid out togather, the 3rd grade brick actually looks a lot like hydrotron. it is even close to the natural color of our clay (tan to light reddish), and is fairly soft, though even today doesn't fall apart in water (absorbs it though). the 1st grade brick is all most black or very dark red and will not absorb water, and is very hard. the 2nd grade brick is between the 2 in softness/hardness, but doesn't absorb water very well either.

thousands and thousands of bricks were made that way here on my place (a small town built out of them actually) and the hole left from the clay mine is my pond today. still a lot of clay down there to use if I want.

[Jonathan Kadish NYC AA Chair]

Cool story and a lot of history there

Larry Poe said:

jonathan,

that is close to the method used when bricks were made here on my place in the late 1800s. clay was mixed with sand or finely crushed reject brick, then dried in the sun. once it had dried, they stacked them into temporary ovens 3 bricks thick (narrow thickness) and built a fire inside the "oven". once it was going good they would close the front and draft and let the brick "cook.

once it was done there was 3 grades of brick. the inside closest to the fire (and cooked the hottest) the middle, and the outside bricks (farthest from the fire and one side totally exposed during the process).

in construction the outside (3rd grade) bricks were used for the inside face of the walls. the inside (1st grade) bricks used on the outside face of the walls and most severe weather facing sides. the middle (2nd grade) bricks were used as fillers and on less weathered outside faces (like the south and east in my area for instance)

my house is built that way and predates 1865 (there are no records in my county before that as the courthouse was burned by federal forces and Kansas jayhawkers during the civil war, so we don't know the exact building date)

when you look at the 3 grades of brick laid out togather, the 3rd grade brick actually looks a lot like hydrotron. it is even close to the natural color of our clay (tan to light reddish), and is fairly soft, though even today doesn't fall apart in water (absorbs it though). the 1st grade brick is all most black or very dark red and will not absorb water, and is very hard. the 2nd grade brick is between the 2 in softness/hardness, but doesn't absorb water very well either.

thousands and thousands of bricks were made that way here on my place (a small town built out of them actually) and the hole left from the clay mine is my pond today. still a lot of clay down there to use if I want.

[Larry Poe]

few photos of what I have built so far. there is also a small (8'x10') cellar under the room on the right hand side of the photo and a large (8' wide by 14' deep) cistern  with a 3'x3' access door in the concrete floor in front of the fridge.