Backyard Aquaponics
A place to discuss aquaponics

Hi!

What types of plastics are "safe" for use as grow beds and tanks? I understand that anything recycled is out, but I'm unsure about PVC/PE/HDPE/LDPE...

I will be purchasing new containers, and understand that I will need to scrub the mold release out of them.

Thanks in advance,

-Ellie

HDPE would be the preference... maybe LDPE might be ok as growbeds.....

Avoid the others (PVC/PE) altogether...

I think there was a tread somewhere in here that talked about these issues and test revealed that HDPE and even LDPE leached no measurable amount into the water. PVC and other plastic did leach a very very small amount. I think its a personal choice as to weather it is acceptable.

What about PP?

PP was discussed in a separate thread. PP was in the thread name. ppl thought it was another peeponics thread, so will be dated some time near but after the peeponics was created...
Can't remember the verdict though

Even the plastic that bottled water comes in leached gnarly toxins... what can ya do?
Yay!

Go modern civilisation!
Making disposable trash out of last forever plastics filled with untreatable toxins since 1945!

For my proof of concept system (which will only be fed to us) I'm going to be using a Rubbermaid HDPE tote for the fish, and a pair of shallow polypropylene* totes for the growbeds. Neither are rated for food use, but I consider this an acceptable level of risk.

Follow up question. Are Pond Liners (The large plastic sheets) food rated, or is it called something else at that scale?

Thanks all,
Ellie

*Probable misspelling aside, this has the same recycling stamp as my daughter's baby bottles.

Which means that they both have similar ingredients, making them recyclable into the same plastic. However recycled plastic is said to be not so nice and leach stuff. This evil stuff has to come from somewhere, and whilst hopefully not from your baby's bottle, there is much debate as to whether it will come from the PP.
Personally I think you'll be fine, there are so many things we are exposed to, we'll never know until we don't have the last few years of our lives

Arn't most people using PVC for their outer standpipes (ie hand graters)?

Well I am, and for most of my plumbing also. Personally I believe something will kill me. Might as well get as many competitors in the race. Make it interesting
if PVC is so bad, then the rain water tanks I drinkfrom all the time would be pure evil.

Some ppl will cite the fact the our water is recirculating through the PVC constantly, and therefore is able to pick up much more leachates. But is this an issue? how much more is more? Can my body handle it? I'm young, and therefore invincible the old folks say, so I'm going to run with that for a bit.

I would say in an aquaponics setup that the PVC surfaces would rapidly develope a 'biofilm' coating that would slow down any leaching by a huge amount. As long as you don't go wiping down the sides all the time it should be fine....
But ya lotta recycled stuff needs a coating of new plastics to keep the nastys safely locked away.