Backyard Aquaponics
A place to discuss aquaponics

J7, i get your point. I know its hard to keep bad chemicals out of a system (especially with city people using rainwater...), but when you know there are potentially dangerous chemicals in a certain thing, you wouldn't try to deliberately add it...

I agree.

why all the worry about lead? I can assure you, you drink plenty of water that's lead contaminated every year. lots of old old piping out there with lead based solder.

There's plenty of other nasties used in PVC to be more concerned about!

I think the proplem is one of recirculating the water time and time again in AP systems. This concentrates the effects of the contaminant substances. In fresh water mains (old piping systems) I think levels would be a lot less than in a recirculating system.

There is no way I would use lead solder in any form in a AP system.

Just digressing a little, humans use pewter beer tankards. (Don't they contain lead?) Also how foodsafe are some of the black pond liner materials?

a quick check for test kits give this site
http://www.lead.org.au/clp/products/Do- ... 70526.html

$80 for two tests or $220 for 8 tests

just rock on down to your local bunnings, they have lead test kits for $40 in their paint section.

I see the point about recirulation though, heavy metals like lead can build up in your fish

a lot of old brass fixtures also contain lead
Sometimes I wonder exactly how much lead is in my bones.
It is in a lot of the food we eat.
metallic lunch anyone?:
http://www.environmentaldefence.ca/reports/metallic.htm

According to Meg in the link below none of us should be using PVC at all. She offers a solution using special garden hoses.

http://365aquaponics.blogspot.ca/2011/0 ... imers.html


I am designing a 275 gallon system. I don't know whether to adopt the supposedly inert garden hose design or if I should stick to PVC. Have any of you had experience with this? Would it get clogged? Any recommendations?

I look forward to your words of wisdom.

Couldn't see anywhere in the blog where Meg mentions anything about PVC.... you can get HDPE "food safe" PVC pipes... or even tubing...

But the hose is probably going to either degrade over time due to sunlight exposure... or fill up with bio-film... and slow the flow....

She's also using brass fittings.... which shouldn't be used... due to metal leaching issues....

You'll see 99.99% of aquaponic systems... using PVC pipe... the rest are probably ex-hydro adaptions... and any tubing/piping under 1"/25mm... is a no go IMO...

P.S... I think it's somewhat bemusing... that she seems so concerned about the possible head loss due to a few fittings... but totally unconcerned about the head loss through the 3-4 times length of hose employed....

rookie mistakes

And you don't want to be turning off your pump at night... unless you've got supplementary aeration set up....

And I don't know how it related to the post... but there's comment about using "pex" in a heating arrangement... pex pipes in a fish tank... circulating water from a solar collector...

Pex... is a pretty lousy heat exchanger.. to heat a fish tank....

Hope they haven't been carried over into the "aquaponics for dummies"...