I use PVC, and I'm assuming that most of you do as well, but there are rumblings out there about it leaching carcinogenic nasties into the water. My understanding is that this happens mainly when the pipe is heated, but that is exactly what we have in the summer.
Is anyone using an alternative in a bigger system? We've used some flexible vinyl tubing...but I sure prefer PVC. Thoughts?
True Rob, but a single trip through a copper, galvanized or pvc, cpvc pipe will have only minimal effect on the water. Constant recirculation is where we really tend to worry most about the pipes and possible leaching.
That said, modern rigid pvc isn't prone to leaching, the major drawbacks with it have to do with it's manufacture (lots of chemicals not so good for environment) and it's disposal (pvc doesn't decompose so it lasts indefinitely in the landfills and burning it releases nasty stuff unless you manage to burn it at a very specific temperature apparently.)
I didn't see any mention of using copper or brass for piping or as valves in this thread, would either of these cause a problem in and AP system?
Yes, metal can cause problems in Aquaponics systems.
Thought, if you are worried about the exposer to sun rays on PVC, they make a round tube insulator for pipe that just slips over the pipe, is easy to cut to sizes and is Cheap. Remindes me of the "noodles" they sell for kids to play with in pools. It would block all uv rays and help with summer heat on your pipes.
This is another case of critical mass needed to change what manufacturers make.
My ideal would be to convince an manufacturer to make a plumbing set specifically for agriculture/ hydroponics/ aquaponics/ aquaculture; a HDPE laminate over "panda" PVC: The outside of the PVC would have a decent layer of zinc oxide as sunblock while the inside of the tube would be black to block and light. These pipes and fittings would then be encased/ fused-laminate with HDPE, inside and out to prevent oxidation and chemical leakage.
Carey? Why not simply use HDPE pipe then?
With all the problems associated with PVC manufacture and I'm not sure the two different plastics are really compatible for "fuzing them together or laminating them." You can't glue or use solvent cement with HDPE. HDPE requires either heat welding or compression fittings which is probably a primary reason that people tend to choose PVC ok well that and the cost.
But I expect and HDPE or one of the other formulations could be made to block light and survive longer in the sun (most HDPE pipe people are used to using is already black) the biggest trick is to find the pipe and appropriate fittings in the sizes needed for aquaponics and within the budget.
OK TC, I concur. Maybe PVC isn't the best choice or most particle but the reason I thought I a good idea is mostly due to the cost factor. However I still say the "Panda" effect (white on the outside & black on the inside) is worth mentioning. Either way, it still takes critical mass for manufacturers to make what we need. Thanks for your comment.
I expect it will be far easier to get "panda" pipe made of just polyethylene, they already make hdpe pipes in all sorts of colors and black/white should be fairly easy. The liner I'm using for my tower troughs is white, black, white Polyethylene.
This is the only pipe I have found that claims to be better than all the other options. The only problem is, currently I don't think the pipe and welding tools are available to the DIY crowd.
u can get hdpe fittings but to get the pipe they want you to buy a mile of it
Rick Op said:
I second TCLynx in PVC manufacture being a primary concern. With an additional footnote that this goes for its eventual disposal too - quite the nightmare!
In between its birth and demise, using it to transport my water, I am not sweating it. With another footnote here that high exposure to sunlight can eventually compromise it.
Which is why I am trying to use HDPE irrigation pipe where possible, where the fittings don't pose a solids buildup issue, and especially where a long run of it is exposed to sun a lot of the time. (It's even kind of fun to work with, pruners can cut it)
But PVC is frankly unavoidable in drain fittings, siphons, etc. and as for environmental impact, I apply the same philosophy as with concrete (for the same reasons) - re-use to minimize need for purchase and disposal.
My 2cents - worth price charged!
I'm fairly certain vinyl is much worse than PVC and I think some people say PVC 'MIGHT' leak BPA, but that's the thing. BPA isn't even necessarily bad. The studies aren't very conclusive on either side. It's never a bad idea to err on the side of caution, but I certainly wouldn't think it's worth moving from PVC pipe to something much more expensive. City water runs on PVC, so there's no way around it for most people even if it is bad and it certainly isn't extremely dangerous or the studies would catch that easily.
PVCvsHDPEvsBPA VS VS VS I think some people loose sight of what they really should be worrying about. We talk so much about what we move our water IN and don't discuss much what is IN our water. For example Flouride (sic?) is an insecticide but we let them put it in our water and smile when they do it. hmmmmmmmm