Backyard Aquaponics
A place to discuss aquaponics

So if anyone has any ideas what to use instead of PVC for the outer standpipes, post them here.

Everything bar Pressure rated pipe has lead and is not rated for potable water especially the sandwiched pipe, the foam being non food safe. I feel comfortable using the dwv in a non drilled application as the surface is not broken (maybe I am wrong and this makes no difference, but there is a limit to my paranoia), but in a drilled application, the dwv pipes and sandwiched pipes are seeming to be unacceptable for closed loop systems like ours.

We are going to use pressure pipe for our new system we are building this weekend (13 tonne of gravel has been delivered) but in the future, maybe a tube could be made out of timber? western red cedar doesn't rot? or hardwood like jarrah? in wa it is cheap? Other ideas?

Stu

You can buy some big diameter bamboo Monya.
Natural, with low embodied energy and totally renewable

Is there a food safe sealant you can paint the pipe with? At least it is peace of mind...

I used a round plastic waste paper bin that already had slots in the side. Cut the bottom out and bang there you go...

I've been quietly talking to Des Boxsell about this issue for a while, mainly in relation to some hydroponics plans.... VB knows a bit about my discussions....

Anyway I talk to Des and Lyn Boxsell tonight and here's the deal....

They will supply their "Ell-Gro" hydroponic channel for BYAP members at special prices..... just mention you're from the "backyardaquaponics forum" when ordering.......


What's so good about "Ell-Gro".....





This stuff is strong, safe and has taken the hydroponic industry by storm.....

The shape and colour mean that there is very little temperature transfer not only of heat in summer.... a major problem in hydroponics.... but also little transferance of cold in winter.

Des has documented photographic proof of the effect of the cold on channels made from "Sure-Gro" PVC and "Ell-Gro" channels, side by side, during the recent cold snap in Qld .

The nutrient in the PVC channels froze and some channels actually suffered physical damage, whereas the Ell-Gro channel showed no ill-effects and a much smaller nutrient temperature drop.... they did not freeze....

You'll also notice on Des's site that he is very aware of the problems with PVC pipe and channels.... and has links to "Greenpeace" articles concerning this subject.... he also says that apart from lead, there is a known "Cadmium" content in PVC....


Boxsell's normally supply their channel in 6 or 12 mtr lenghts with pre-drilled holes at predetermined intervals..... great if you want to incorporate growing something in your return lines....

But Des will provide both lengths to BYAP members in undrilled lengths. The "special" price equates to about a $2 discount per 6mtr length... about $22/6mtr......

http://www.boxsellhydroponics.com.au/

Certainly could be used to relace your return lines and could probably be used for standpipes, possibly with a bit of adaption....


The other choice.. is the Sure-Gro channel.... http://www.advanceprofiletech.com.au/

Great for return pipes and utilising as extra grow capacity.... but not practical for standpipes .... and is made from PVC ....

Has the nice advantage of being able to clip off the top to allow for cleaning.... however the Ell-Gro channel has proven to be exceptionally easy to clean with a pull through brush and/or rag....

As a footnote, Boxsells own and operate their own extrusion plant that produces the "Ell-Gro" products....

The channel comes in two sizes 120mm x 53mm and 182mm x 70mm

http://www.boxsellhydroponics.com.au/Channel.html

Good one Rupert. I'll definitelly be talking to Des in the future :-)

like the bamboo idea LB

So do I - but people need to make sure that if they buy the stuff, rather than get it themselves from a clump or something, that they need to make sure it is not treated.

Hummm.... Bamboo leaves are poisonous, and I pretty sure bamboo is poisonous to cats and dogs....

And there's this ....

http://www.inbar.int/publication/txt/IN ... r_No39.htm

how about something like this? Prob abit big.....
http://paramountbrowns.ihub.com.au/Desk ... ntbrownsau

just a hole in the bottom big enough for the standpipe to go into, and the top cut off (and drill, or hot poker lotsa holes), and it should still be ridgid

Did you know someone who liked welding stainless steel or aluminium?
http://paramountbrowns.ihub.com.au/Desk ... ntbrownsau
but then you wouldnt really need to weld it, just a coil and hold it in place til the gravel locks it in place.....would 0.7mm steel be easy to manipulate? (i wouldn't think so....)

not sure if they would work out cheaper or easier than the pp though...

What about ceramics, like a reused terra cotta pot or a cylinder made of fired clay?

great idea dave, wouldnt terracotta give more surface area for the bacteria too ?

Maybe a little, I like the idea of "sticking it to the man" by not using petrochemical products if possible. Another plus is that it is a primitive material - you could make it from dirt and water.

My outer standpipes are constructed from heavy duty screening like you might make a rabbit hutch from. The wire is galvanized so it hasn't rusted.