Backyard Aquaponics
A place to discuss aquaponics

I was wondering if anyone had anything they could offer in the way of information on home made LECA type material. I have all the clay I could ever want and was thinking of making a kiln to fire the clay. I am not sure, however, if there are any methods I could use to make the clay porous or if I had to seal the clay in any way before or after firing. Has anyone ever tried this themselves? Or does anyone have any ideas? So far I thought about possibly....using a melon baller and scooping them out individually, making a half sphere mold and filling/punching it out, or making long clay "ropes" and cutting the ropes into small pieces.

Before anyone tells me how long it would take to make a grow media myself and how much effort I would have to expend, let me just say that I live on a farm in the country. Here I have a lot of time and limited resources, so I am trying to do the most that I can with minimal purchases. Thus, I am exploring the idea of making my own grow media. Any information would be greatly appreciated!

I know that there has been talk on here about trying to make your own hydraton style clay balls. I cant seem to find it now though...

BullwinkleII would be the person to chime in here as our resident clay expert.

Using a melon baller to make that many though makes my skin crawl!

Very high heat, hotter than you would ever think was reasonable to fire clay at, is the key. I believe that the idea is to have the clay puff up like popcorn. That is what gives it it's porosity.

The clay you need to use has to be a special clay, I think it has some natural gas particels trapped in the caly at time of formation, that is why it pops, all I can say is that my clay really smells like sulfur, probaly some kind of vulcanic clay. I've seen the machine that makes it and they look very weird! like a giant axial fan!

Here is a thread started by Bullwinkell titled Home made goat dung scoria recipe

Thanks for the info, everyone. I have read through Bullwinkle's post and am a lot more confident that it can be done now. I dont have goat manure, but do have a lot of chicken poop to deal with. He supposedly made it from clay in from his backyard, and I will try to do the same. No clue if it will work, but anything that I can do myself is better than paying money for it!!

A bit more research, then let the experimenting begin!

Make sure you keep us update

The goat dung was just included as organic material that would burn out and leave holes/extra surface area for bacteria to colonize. The result would be more like a cross between scoria and expanded clay balls.

Goat dung was chosen because it's available everywhere, and if you have hay, it might be best to run it through your goats first to get the benefit of feed, rather than wasting the calorific content by burning it before running it through a goat.

If anyone is reading this 8+ years later, the pottery terms to search for are "clay" and "bloating" to get a result more like the expanded clay balls we all love. That search will tell you how to avoid it, because we hate it in the pottery world. But I guess... just do the opposite

Scoria is glass-like but has a stack of bubbles to give it surface area, and the expanded clay balls achieve the extra surface area by ballooning up (as someone mentioned - like popcorn) and as a result the clay performs like ...say a bit of crunchy cloth might if your stretched it - or... like popcorn . ie it kind of cracks on the surface and massively adds to it's surface area. I'm guessing expanded clay balls also leak water into it's internal space which looks like a micro-honeycomb, and allows even more space for the beasties to live.

But maybe not, because that internal space might be anaerobic.

I think, for aquaponics, a blend between the two might actually work better.

Expanded clay balls, but with organic matter like sawdust or straw (or goat dung at a pinch) might be the best of both worlds.

This would be fun!
I know someone mentioned going to a super high temp to pop the clay. Now I want popcorn!

The idea of mixing organics in to create pores is a good one, or a great one...


From my experience with regular clay, higher temps, like is normally used for high fire clay results in a more glass like clay body with less pores.

Lower temps lend to a more porous fired clay body, but also more fragile.

I think hydroton is heated high and fast.

If it was shaped into pebbles like hydroton, I don't think the fragility of low fire would matter. Hydroton is kind of fragile itself. At least when I step on it.

I agree that the type of clay can make a difference too. Free clay though, would be the best type to play with...it can be pricey here.

Ollas or clay pots were traditionally used for sub surface watering, and are made out of low fire clay, which allows the water to seep through.

I've experimented with making a few ollas....but my temps were too high, so they don't seep the water very well.