Backyard Aquaponics
A place to discuss aquaponics

I agree that glass slivers or powder would be a risk for the operator, so a good quality mask and eye protection would be a must. But my understanding is that by tumbling the glass with water, and keeping a lid on the mixer, this isn't really a big problem. Did you watch the video?

There is no clay on the island, much to my disappointment.

Nothing wrong with HPDE plastics the only residues I'd consider would be the nasties in the residues of the soft drinks (some of which are pretty nasty I will admit).

Preparing them would be very simple and very quick just pass them through a garden shredder.

I like media beds because I think they are a good solution but while they have many pros they also have a few cons. In your situation there are extra and larger cons why go to so much effort to have a media based system what is the advantage?

Well everyone seems to dislike your idea, but I think it's wonderful. Here in california we have glass beaches, where people have used the ocean as a waste dump in the past. Because the glass beaches are so pretty, the government is now purposely dumping glass there to replenish the glass beaches. The tumbled (by the ocean) glass is smooth and very similar to polished rock. It is not as dangerous as others have suggested.

I have done a bit of rock polishing. You do it the same way, in a tumbler. I never thought of using a concrete tumbler.

Glass as a grow bed media would be great. It is PH neutral and lighter than gravel. If polished smooth it would be soft on your hands (unlike my scoria/lava rock).

Light penetration could be controlled the same way you do in a regular bed. Shade the grow bed. I cover the outside of my grow bed containers (IBCs, which let in a ton of light) and have shade cloth over the tops. This controls the algae growing on the inside of the container and on the top of the gravel where the water splashes in.

Just like any other media, you would want to wash it to remove the dust. However, any dust that did get in the system would be covered by biofilm and absorbed into the grow beds. Clay particles are very small compared to sand (glass by product) and clay is aborbed into the grow beds just fine. It sticks to the microbes in the grow beds.

I say try it. Who knows, it might even become the media of choice.

Glass is dangerous. Glass powder is really dangerous. It is entirely possible to manage the risk posed by a substance and in some/many cases the risk can essentially be eliminated. Tumbling the glass in water is great step to reduce/eliminate the risk of glass powder but what happens to the glass powder afterwards. If it ends up on the ground it could later dry out and become wind blown. Not a good idea.

Around here we have a number of quartz quarries. A MAJOR health risk they have to manage is avoiding their workers being exposed to quartz dust. 140 years ago there was a very common complaint in this area called "Miners Lung". Essentially gold miners would have their lungs cut to shreds by tiny slivers of quartz that they had sucked into their lungs. Also an increased incidence of lung cancer. A lump of quartz is pretty safe as materials go, unless it falls on you. Once you start breaking it up though it poses a small risk. If you break up a lot it starts to pose a big risk.

I am not saying it is not a good idea or that it cant be done or that it cant be done safely. However, if you don't think it through it could be bad not just for you but for others.

Could it be produced like lead shot dropped from a height into cold liquid?

Is it worth the trouble?

Not such a good Idea because I think that unless you had a shot tower you would end up with spiky strands.

The only worry I would really have would be the cost of doing it, any residue could be mixed in cement (another nasty substance to work with) for construction purposes.

Yeah it would be a big job and any waste wouldn't be a problem as long as it was dealt with appropriately both when it was being created and later.

Thing is I've seen people not take these things into account all to often. When I was an environmental consultant waste and it previous inappropriate creation, storage and disposal was one of our big money earners. As well as writing up plans so the that problems were not created in the first place.

Good summary you posted there, it will certainly help people out on their choices.
I have a pond at home (nor for aquaponics) and i use lava stones because they can hold more bacteria then clay pebbles. Could you use these for your aquaponics system as a grow media?

Thanks

Can and do use them. They work great as a grow bed media. Only disadvantage is they are course to the touch. I use a small trowel to remove rocks for planting. Actually I use a trick, placing two trowels together and forcing them into the media by shaking it as I push in. Then spread the two trowels to form a cavity where I pop the plant in. Remove trowels and the cavity closes in.

So hydroton isn't really available in my locality, I had searched for it when setting up my systems years ago but no luck. Been using river rock which works fine but is expensive and heavy.

Was out looking for an alternate when I got a line on getting some clay balls custom made for me.

I don't have details on the pricing dynamic as yet, but you guys think they could be used as a replacement for hydroton? What measures would I need to insure to make it what it needs to be?

If it works out I'll use the clay balls as the top half of my GB with large river rock making up the bottom.

2016-04-12 To followup on this media test I did....polyester batting did not work. It is pH neutral and does not absorb water, however, water did stay trapped between the fibers too much, which kept things overly wet and had algae/mold growth. It traped water so well it eventually got weighed down. It still held the water when I was throwing it out.

Thanks for the update

i use exposed aggregate, it is used on concrete paths and driveways as a decorative finish. It is mixed aggregate tumbled so there are no sharp edges. The pros are it does not bind together and it is not harsh on your bare hands. The cons are it is about $20.00 more expensive than blue metal 20 mm per cubic metre. I have also used 40mm blue granite aggregate which is left on the roadside after road works around here. The 40 mm is okay but hard to dig in.

In essence, it acted like sand.