Are PVC pond liners safe to use?

[Desert Hydro]

i have used pond liners before and not had any issues but i didnt realize there were multiple types(PVC and EPDM or whatever) the one i ordered ended up being the PVC one. it says its plant and fish safe. my plants seem to be experiencing some yellowing but it could just be the shock of going from t5 to a 1k hps. its about 3' away though.

temps are in check, EC, ph are in check as well. maybe im just paranoid but i would be grateful if anyone could chime in on the matter

 

[TnTLabs]

ive only used the pvc ones as a runoff deposit..so no contact with plants, how do you use it?
souds like light stress... they need more food

 

[corky1968]

PVC should be ok. They use that in plumbing now.

It's probably the intense light they now have that it's causing the yellowing.

Same thing happens when you take a seedling and place it under direct sunlight.

Raise the light up as high as you can for the 1st couple of days and lower it 6" at a time until you get to the safe zone.

 

[HuffnPufferfish]

Degradation

Degradation during service life, or after careless disposal, is a chemical change that drastically reduces the average molecular weight of the polyvinyl chloride polymer. Since the mechanical integrity of a plastic depends on its high average molecular weight, wear and tear inevitably weakens the material. Weathering degradation of plastics results in their surface embrittlement and microcracking, yielding microparticles that continue on in the environment. Also known as microplastics, these particles act like sponges and soak up Persistent Organic Pollutants (POPs) around them. Thus laden with high levels of POPs, the microparticles are often ingested by organisms in the biosphere.

However, there is evidence that three of the polymers (HDPE, LDPE, and PP) consistently soaked up POPs at concentrations an order of magnitude higher than did the remaining two (PVC and PET). After 12 months of exposure, for example, there was a 34-fold difference in average total POPs amassed on LDPE compared to PET at one location. At another site, average total POPs adhered to HDPE was nearly 30 times that of PVC. The researchers think that differences in the size and shape of the polymer molecules can explain why some accumulate more pollutants than others.[30] The fungus Aspergillus fumigatus effectively degrades plasticized PVC.[31] Phanerochaete chrysosporium was grown on PVC in a mineral salt agar.[32] Phanerochaete chrysosporium, Lentinus tigrinus, Aspergillus niger, and Aspergillus sydowii can effectively degrade PVC.[33]

so its considered "safe"

 

[corky1968]

If you have this Aspergillus stuff the least of you worries will be the PVC.

 

[Drop That Sound]

All PVC off gasses for awhile after its made, plus everything is cheap garbage now nothing is safe, especially when subjected to harsh environments that it wasn't designed for. Manufacturers are known for using fake test data, and even when caught, their products still are sitting on the shelves of stores that are like 60 times higher than the allowed amounts of toxic chemicals. They just "phase out" the products in like 2 years, by then someone got some new chemical and the vicious cycle repeats. Mostly imported stuff i'm sure but who can you really trust these days?

That being said I like to at least let the materials sit in a a garage or outside for a few months to off gas before blasting it with HIDs, and checking the date on it helps to be safe.

Don't take my word for it though I've worked around too much plastic\acrylics, composites,resins and flooring and all that crap, and have plenty of heavy metals accumulated in my body and breathed in my body weight in dust to the point my brains damaged a little. You'll be alright

 

[Desert Hydro]

thanks everyone. i had a long post written and it got erased. the pond liner will soon be covered with a coco mat so it wont be getting direct light.

 

[queequeg152]

pvc requires plasticizes like pthalates to allow the cross linking that allows for shit to be pliable.

pthalates however... make pvc decompose over time with uv light.

the most stable pvc is so called "UPVC" or non plasticized pvc... its the stuff the stuff they make windows and siding from. you cannot solvent weld it and its prone to fatigue... so its not terribly useful in plumbing or anything as it has to be welded with heat and pressure.

yes almost all plasticized pvc will out gas... but this level should plummet to close to nothing rather quickly.

are plants sensitive to pthalates though? ive never heard of that.

 

[Drop That Sound]

I've head of people losing crops consecutively in tents made with cheap pvc fittings, not only from toxic gas but some from the material getting brittle to the point the roof collapses and gear dropping down on the plants.

If it starts turning color or changing its properties that means there is a reaction going on and there will always be by-products from a reaction. Those by products gotta go somewhere, and probably not very far from inside your house...

 

[queequeg152]

yea i heard about the hoses out gassing and shit from way back... i dont grow indoors though so i didnt pay much attention.

i thought this was from ethylene though, not plasticizes. could easily be wrong here.

 

[Dion]

yes