Aquaponics and plastic system materials

I’ve had many people ask me about PVC and “Risky” plastics and I suppose I need to post about it.

Here is the latest answer I gave.

You need to make a distinction between rigid opaque PVC (like plumbing) and the flexible vinyl that may contain nasty plasticizers (even if certified “food grade” or “Potable water safe”)

The Rigid pvc plumbing doesn’t contain the nasty plasticizers that can leach and play havoc with hormones and stuff like that. The objections to rigid pvc plumbing and health would be related to the manufacture of the stuff and the environment around those plants. Rigid PVC isn’t releasing nasty stuff into the air or water, unless you are burning it or something like that. (Just don’t use really really old stuff, because I suppose it’s possible it could have lead in it. Kinda like the lead paint sort of issue.)

The Flexible PVC (vinyl liners, flexible hoses, garden hoses,) I don’t like much. It requires plasticizers to keep it flexible and more stuff to keep it from getting brittle in the sun too fast and those things all tend to escape “leach.” Non potable water grade Garden hoses could even leach lead.

So, I agree that sticking with the polyethylene plastic made from FDA/USDA approved resins as much as possible is a good idea, however, I don’t have the budget to use the Large size HDPE pipe I would need for large scale systems so I still use rigid pvc plastic and fittings. I also use uniseals which are not made from specifically approved resin but I know there have been articles manufactured with parts made from that same resin that have been approved for potable water or food contact use.

I choose my materials with care but I’m not the sort to go to the extreme of insisting it ALL be labeled food grade (after all, many of those nasty plasticizers people are so freaked out about are approved for use in food grade plastics.) I personally feel comfortable enough using stock thanks made from HDPE structural foam plastic. I won’t tell you to do the same though, I believe we should make our own decisions.

I also use lots of submersible pumps since the design of my systems (outdoors with in ground sumps) would make trying to use inline pumps problematic. All pumps need to be fish safe (no oil and no metals other than stainless in contact with water) only plastics issue I see is the short bit of the power cord in contact with the fish water. Then again, though I don’t like flexible vinyl, I’m still using a fair amount of it for the air tubing. Ya gotta do what you can. If you have an affordable recommendations for alternatives to 3/8″ and 3/16″ tubing for the air stones let me know.

For my commercial aquaponics system I make a point of NOT re-using used IBC’s even through I know what was in them. I save the safe to use IBC’s for my personal gardens or the duck-a-ponics filter.

I advocate using some care and doing some research to figure out what materials seem most appropriate (don’t simply using something because you saw a youtube video of some one using it) but I am also not an alarmist, at some point you have to choose something you can actually afford and grow some food.

I hope that helps and didn’t seem too evasive.

I also went on to comment in a further e-mail

I am of the opinion that is it better to

    do something

by way of growing one’s own food even if some of the materials might be less than perfect. Do what you can to choose the best materials available within your means BUT Don’t let panic over plastic stop you from getting started.

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