Backyard Aquaponics
A place to discuss aquaponics

Hopefully I am using this forum correctly. Any help in correct protocol gladly accepted.

The issue for me now is to design the best system using, if I can, ground glass. My work involves disposing of a quantity of glass, and I have found that ground to a certain thickness it can be used with compost as a potting mix. The glass has improved the porosity of compost that previously could not be used in the potting mix.

If I can develop the aquaponics system around a growing bed of ground glass, then that would fit very well with our present business.

Any experience or thoughts on this would be appreciated.

We saw a program resently on the ABC, one of those home building shows. There is a guy in England who uses recycled glass to make bath tubs and wash basins.

Hi Ashley, welcome to the forum

What an interesting concept. How thick is the "certain thickness" ? I seem to recall someone talking about using glass pebbles in their growbeds, but I don't know what happened with it. I'll get back to you.

hmmm how big are the pieces... if ground, you'd want to mix it with larger media, even then it may get through your pumps and ruin them.
If coarsely crushed, it should work, but you have an evil medium in which to put your fingers to plant, and the risk of glass on your veggies would be very high. But hey, try it out, I'd be interested.

It would be neat if the glass its self was 1" or so... but for planting a shovel is a must! lol!

KT I'd still be worried about glass in my food... Especially if I was running a market stall

If the glass has been tumbled to smooth off the sharp edges, and sieved ( washed? ) to remove the fines which could cause issues with water retention, I see that it could be a useful medium. The smooth edges would be frosted b the tumbling to give a larger surface area.

The weight may be an issue. Any idea of the relative density of glass, gravel and saturated Hydrotron?

This would be an excellent means of re-use of glass where local recycling facilities may not be practical (eg, no glass recycling facility in West Aust. All is sent to East for recycling)

It may be of benefit to do a cost audit of the benefits of this compared to transporting the glass for recycling.

There is some glass which is impractical for us to send for recycling, either due to small volumes or high transport costs. This could provide an inexpensive local re-use solution.

any glass recycling is crap, reuse is much better. The max possible percentage of recycled glass in new products is rather despairingly low. I'm all for it as long as there's no suit for ingested glass giving AP a bad name...

standard joke around here is; Have you got the ratio of cyanide/crushed glass right in the tea/lunch?

I have actually attempted to make "beach glass" before. It is pretty hard on the tumbler if the glass is sharp to begin with but if done for long enough with the right grit, you get a frosted surface and rounded edges in the process.

I expect that after that treatment the fines left behind are little more than rather silica heavy sand. Probably not much more dangerous than eating food grown in perlite though I'm no expert.

The density of glass is typically about the same as granite: 2.6 g/cc. The density of gravel would depend on what rock it comes from, but this is probably a good number. Hydroton is about 1g/cc dry (a lot of it floats, so must be same as water), but someone who has some will need to do the calcs. My guess would be between 1g and 1.5g/cc. So glass would weigh about twice as much as hydroton.

I'd love to see glass made into a foam, then formed to make rounded nuggets, but the energy input would probably make it more costly than hydroton. Might form into a nice, insulated, translucent building material as well.

It is really good in concrete and polished!!!

expanded glass... interesting idea...

what blowing agent wold you use?

from http://www.answers.com/topic/foam-glass?cat=technology

foam glass
(′fōm ′glas)

(materials) A light, black, opaque, cellular glass made by adding powdered carbon to crushed glass and firing the mixture.