Various Grow bed media

RupertofOZ

Minimum 12-15mm IMO....

tangito

Thanks Rupert,
In my haste/excitement i made my grow beds 350 deep. /i guess i will fill it 300 deep. going to be heavy

tulip

Great information dude, particularly the point which I really got inspired that is Perlite that point is really helpful and able of appreciation.

Best Regard:

Zeknix

With the topic of using glass as a medium, I'm surprised that no one has even talked about Growstone. It uses recycled glass as its main ingredient. Its made in the USA so not sure if its available outside the USA for now. I'm using it in one of my small growbeds right now to test it out.

Initially I had a problem with the pH staying high in the system. Eventually it went down. After reading the MSDS, I found out that they use Calcium Carbonate as a foaming agent during production. It took awhile for the system to consume the carbonates but now its not a problem. Guess you could let them soak in water overnight and discard the water to try and lower the carbonates. I didn't worry about it too much.

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File comment: Bed #2 Growstones

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File comment: Cucumber Seedling I forgot about.

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mantis

tangito wrote:

reading through the above posts gives a wide range of opinions. What would be the concensus on size of media. I'm thinking fravel/crushed rock..

You can have different sized media in different beds. Smaller media is better for sowing small seeds and the bigger media is great for seedlings and larger plants like tomatoes

aponadam

TCLynx wrote:

people have talked about the recycled glass before. I think most of it tends to be way too small, more like sand.

However, if you could get large amounts of the darker colored stuff in aprox 1/2" size that would probably be fine though it will let more light further down into the bed than most other media will.

I am seriously considering doing this. If anyone has tried this, I'd love to hear about the results.

I live on a small island in The Bahamas and have a large commercial-scale DWC system. I desperately want to add in media beds but media here is prohibitively expensive. The price of hydroton, including the cost of getting it here, is roughly $40 per one 50L bag, and for the size of my system I would need about 6,000+ liters (6 cubic meters). That would be $4800... There is no other rock here on the island other than limestone so any other gravel would also have to be imported and because it's so heavy, would also cost quite a lot.

So I have thousands of glass bottles (and enough dark brown ones so that I could use those exclusively) here at my disposal, and I'm pretty sure my work owns a concrete mixer. Really excited at the prospect of finding a great use for a waste product while potentially solving my growbed media dilemma!

How long it would take to tumble the glass to the point where there were no more sharp edges? Would I be able to tumble the glass in a way that maintains the fragments at larger sizes without making them all so tiny that they would be useless to me? I doubt anyone has any answers to these qustions, but these are the questions that are rattling around in my brain right now and I'm curious to find out the answers by giving it a try.

scotty435

I would think that by tumbling them some glass would be broken so you'd never get rid of all the sharp edges. I think some places heat the glass in a kiln for this but I'm not sure.

How are you filtering your water now?

Stuart Chignell

aponadam wrote:

How long it would take to tumble the glass to the point where there were no more sharp edges? Would I be able to tumble the glass in a way that maintains the fragments at larger sizes without making them all so tiny that they would be useless to me? I doubt anyone has any answers to these qustions, but these are the questions that are rattling around in my brain right now and I'm curious to find out the answers by giving it a try.

First to answer your question, ask the ocean because I've got no idea. 2nd think about the process and the waste you would be creating. I don't know what the waste would look like but I imagine after a while you would have vaguely smooth glass stones and a whole lot of seriously nasty slivers and glass powder. Maybe this could be reused but you are talking about a rather large industrial process just to round the glass shards let alone process the waste.

My advice, don't fight your environment. If you don't have gravel and don't have an alternative don't build a media system. Install RFF, Biofilters and run all or almost all your plant growth in DWC, rockwool or some other manner where you don't need gravel or the equivalent.

aponadam

Stuart Chignell wrote:

First to answer your question, ask the ocean because I've got no idea. 2nd think about the process and the waste you would be creating. I don't know what the waste would look like but I imagine after a while you would have vaguely smooth glass stones and a whole lot of seriously nasty slivers and glass powder.

There is no recycling of glass on this island. So the waste already exists. I would not be creating any waste. If I can reuse 90% of the glass in a bottle and have the remaining 10% as sand and glass powder, I'd be thrilled with that. Plus, I can always mix the sand and powder into concrete mixes to utilize that waste stream as well. No waste.

Quote:

My advice, don't fight your environment. If you don't have gravel and don't have an alternative don't build a media system. Install RFF, Biofilters and run all or almost all your plant growth in DWC, rockwool or some other manner where you don't need gravel or the equivalent.

You may be right about that, but I'm not entirely convinced yet that glass isn't a suitable alternative for where I live. I will keep looking into this and maybe try tumbling some glass until I find that it either works or doesn't work.

Colum Black-Byron

I'm just picturing all the tiny glass shards getting into the gills of the fish.

What about brick gravel or something? Just get the mortar off and it should be alright. I saw another member that used plastic bottle lids. It was a little too light, but worked.

I'm having trouble believing there isn't at least blue metal there. It's what's used in roads.

However, your system seems quite well set up, if it's not broken, don't fix it.

aponadam

Colum Black-Byron wrote:

I'm just picturing all the tiny glass shards getting into the gills of the fish.

What about brick gravel or something? Just get the mortar off and it should be alright. I saw another member that used plastic bottle lids. It was a little too light, but worked.

I'm having trouble believing there isn't at least blue metal there. It's what's used in roads.

However, your system seems quite well set up, if it's not broken, don't fix it.

I don't think after tumbling and rinsing the glass there will should any shards remaining. And really after tumbling there won't be any shards period. Just sand. Check out this video. Seems pretty straightforward and the finished product really looks like it could work in aquaponics.

No bricks here. Concrete block is used for everything. And no blue metal either, limestone for everything. Really is a small island; only a few thousand people here.

I don't think the system is really that well set up. It could be producing way more than it is and there is way too much sludge in our raft beds to the point where it uses up a lot of the DO. I'm very much intent on getting things working properly.

Colum Black-Byron

Make up a batch, see what it's like.

The only other worry I'd have apart from it being sharp (and be careful when planting in it, or chunks breaking when it's being shovelled into the bed), I'm not sure how much light it'd let though, too much, and you'll have algae problems.

If you're getting layers of sludge across the bottom of the beds, I'd imagine your filtration/polishers aren't up to scratch. A system that size is a bit out of my knowledge level, but I know there are a few here that could help.

Stuart Chignell

Even if that waste is valuable or even just because you are not wasting a waste doesn't mean you are not producing a waste. By product is a better term but glass slivers or powder may represent significant risks.

Is there any clay on the island?

Stuart Chignell

If there is no recycling then start a recycling program and shred all the HDPE bottles for media instead.

aponadam

Stuart Chignell wrote:

If there is no recycling then start a recycling program and shred all the HDPE bottles for media instead.

These would float, would they not? Using such a large volume, I'd be worried about the chemicals leaching out of them as well. Also, seems like it would be just as much work, if not more so, than tumbling glass.

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