Backyard Aquaponics
A place to discuss aquaponics

rain water is used as drinking water at least for animals and often for humans too

I am not trying to be an advocate for PVC
as said before, I am opposed to it
but we are not left much choice

I just detest hearsay and urban legends

so please give me links where is shown that the lead used in PVC risks leaching into the water

frank

Oils aint oils... plastics aint plastics.... and not all plastics and PVC is the same...

Much discussion has taken place on the forum over several years and several dedicated threads (:wink:) concerning this issue...

And food grade PDHE plastic products are those recommended for use in the acidic nature of aquaponics...

Indeed PDHE food grade plastics were specifically developed due to health concerns of leachates from PVC....

Most/nearly all electrical conduit and stormwater PVC piping/conduit doesn't, by nature of application, require such constraints...

However the industry is virtually to a man changing away from "coloured" plastics..... and industry isn't exactly forthcoming into rushing into change just because of a "green" whim...

Even the hydroponics industry is changing the composition of the PVC utilised in hydroponic channels, and indeed here in Australia, one manufacturer makes exclusively "food grade" products...

Lead is a particularly nasty product that accumulates readily in the human body... as has devastating effects on brain developement in young children....

It's affect has been widely know for decades... and paints have been modified to be lead free for many years... as has petrol.....

Similarly, due to concerns about "cumulative" affects of copper.... all new homes no longer use copper piping for water supply.... but a PVC piping..

The evidence of leads affect on humans is widely known and excepted...

In regard to "plastics" and PVC.... Greenpeace has (on their website) comprehensive information regarding the "safety" of various PVC groups.... and lists a "plastics" pyramid...

Food grade PDHE PVC is at the lowest level of concern.. even for that organisation.... look it up...

Here you go... made it easy for ya... http://archive.greenpeace.org/toxics/pv ... e/bad.html

[url]bad.html[/url]
ROFL

I agree with all the objections to PVC
it's brittleness in cold temperatures is another important point

the Greenhouse paper doesn't mention lead

but there is no alternative for thin walled pipes
believe me, I have searched

HDPE and PP do not lend themselves very well to pipe manufacturing as they seem to lack rigidity
the greenpeace paper contradicts that, but I have not found hard HDPE or PP pipes

I am now speaking with a friend who owns an extrusion company to have pipes and other profiles extruded in PC

not much better than PVC, but rigid and virtually indestructible.
you can take a hammer to it.
which for long term applications reduces the impact on the environment

but I will also look at the "hard" versions of HDPE and PP

truly a difficult enigma to solve
all help is welcome

frank

OK... as a public health service.... .... (google is your friend )...

http://www.vinyl.org.au/environment/heatstabilisers.cfm

http://lists.essential.org/1996/dioxin-l/msg00205.html

http://grandorth.com/pvc_pipe.htm

http://www.turnertoys.com/pvc3Stabilizers.htm

http://www.checnet.org/healtheHouse/edu ... ain_ID=148

Just a few... but they all recognise the use of lead stabilsers....

why again this yes/no discussion, Rupe?
I am not contesting the presence of lead, only asking whether it risks contaminating the water.
the point of this discussion TMHO is to determine whether PVC should be banned from AP because of the risk of lead leaching into the water

even if that should be established, which it is not so far, not even by greenpeace,
there is still the question of an alternative that stays unanswered
I am very annoyed with PVC and have stated this before

that is why I will continue looking for an alternative



frank

Theres lead in my PVC. I mainly use the black pipe for the pressure side. And most of my other PVC bits are high pressure and are used with low pressure. Biofilm covers a lot of it over time but AP water is acidic. And acid is stored in plastic. I'm on the fence so far. But I don't like any heavy metal in my salads.

you could always try weighing your lettuce leaves... maybe if they sink quickly in water, they could be full of heavy metals.
While it's a concern, I don't think of all the things that will kill us, lead is one of them, but hey, you never know.
Surely some1 with a commercial system would have to have their system looked at for health regs... fish may have been tested for such contaminants?
Any thoughts from our commercial friends?

you guys make me laugh:)