Backyard Aquaponics
A place to discuss aquaponics

I saw these large square food crates at a produce place where I got my greenhouse plastic from, got all excited, got closer and realised they had ventilation holes all over them DOH!

Stu - would love to get my hands on some of that extruded poly you are using. Can u tell me a bit more about it. What is it normally used for? How thick is it? Does it go by some name? How much is it costing you? What is the nature of the business of the mob u are getting it from, I want to source someone similar in Brisbane.

Thanks.

VB It's 180 um thick, called "Thermax dura-film". It has a "install this side up decal, which recons its condensation resistant. I think it's made in Canada. Cost me $8.95 plm at 7.5 m wide. Specifically made for the application. I got their number from a mob who makes similar stuff but only sells it in 100m rolls. I got it from a produce supplies shop ie they sell vegie boxes, plastics. Was a bit of a search. I think they would be found under "plastics in the yellow pages. See how you go, let me knowif you find some, I might be able to help if you can't

Cool Stu. Sounds like Duratough 180micron. Redpath stocks this and could get it for a similar price to what you paid but would have to buy a larger quantity. For the quanity I need - would proably have to pay nearly twice what you paid - unless I could find someone in Brisbane to share the order. Will wait until I am ready for it to go down this path.

Thanks.

I was wondering about the use of the black builders plastic you can buy at hardware stores as a liner for an in ground pond and plant growing area. I have googled it and come up with it being probably polyethylene. I found a site that says the same thing someone else said a few pages back...that its also used for icecream lids, etc (found this site, has bunch of other plastics too.... http://www.visyrecycling.com.au/images/ ... ics_ID.doc )

So Should this stuff be safe for fish and plants to be grown in for human consumption?


Cheers (oh and interesting discussion about the PVC )

I have answered my own question, and I am now relieved (wasn't looking forward to spending $400 rather than $30 on a liner)

heres some interesting information about liners (taken from http://rps.uvi.edu/AES/Aquaculture/components.html )for those interested.....

"6 hydroponic tank liners Low Density Polyethylene (LDPE) 104' x 9' x 20mil We have tested 5 different liner types and find this to be the best. Vinyl liners deteriorate in the sun and shrink when dried. Thicker polyethylene (60 mil) or High Density (HDPE) is more brittle and difficult to shape into the tank corners. A Permalon7 liner had a short life"

I wouldn't use it for that purpose personally.

problem from what i can gather is not the material per se, but the manufacturing process and source of the raw materials. foodgrade PE uses much more pure stock, where as general use PE probably uses recycled PE which may introduce contaminants

What you are after is virgin plastic. If you find a cheaper liner of virgin plastic I'm all ears. Murrays liners on his website (you'll find a link here look for growbed thread or recent float switch thread) look to be an economically viable option for those on a budget. Take a look at IBC's too Daniel. Intenational bulk containers. These are 1000 litres, need to be food grade (many are) and can be sunk in the ground for structural support leaving the cage to frame a mini greenhouse/nursery.

VB look here www.aquaponics.net.au
Little bit Stu got but it is 190 um and is made specifically for the Agriculture industry and there is a surcharge built into the price for buying cut length.
You can order any length you like.
Good stuff

Muzza

the liners at www.aquaponics.net.au, are they the strechy kind?
Also, am i understanding right, that they can be ordered in a "any length you like." ?
Lastly, can say Black PVC Quality pond liner 2 metres x 3 metres x .5mm thick be safely (no leaks, or leeching of chemicals) attached to a Black PVC Quality pond liner 5 metres x 6 metres x .5mm thick? My current setup (really just a hole atm) is an odd shaped, has basically a river flowing into a pond.



Thanks

I would be thinking that leeching is an issue.
Thinking even more reason to use old stuff where the majority of the leeching would have happened.
Also there are types of CVT clear vinyl tubing that are 'food grade' and used in beverage making and stuff. That will be the way I will go, also allow one to see the inside of ones lines. Then just need big bottle brush to clean now and then(If required)

think I was a bit out of step there.

so is every one worrying about the leaching harming the fish, the olants or both.

The issue is harming the humans eating the plants and fish. No point grwoing organic stuff full of leached chemicals.