I just got back from browsing Lowe's. There I saw some grey schedule 40 PVC that is meant for electrical conduit. One of the fittings was a 90° bend with a large radius...4 of them would make a 2 foot circle. I asked the helpful child there if I could use this for water since the white schedule 40 is for water. His response was "It's not rated for water. The only plastic that is is CPVC. PVC will leach chemicals into the water. The white stuff in the plumbing department is for exhaust and waste only."

Isn't white schedule 40 PVC recommended for pond plumbing? Is there a difference between this and grey electrical schedule 40 PVC? If I could use this, it would save a lot of money over the flex PVC that's used to make gentle bends.

If there is a difference, and the white stuff is ok, does anyone have a source for large radius elbows?

Hi Linda, I have used the grey fittings when I couldn't find the white ones of the correct size. I have quite a few of the grey ones throughout my pond pump and filter system with no problems.

While the gray PVC may leach more, if you're only using the fittings, very little will be contacting the water. I wouldn't use it for long stretches of pipe though.

Leaching of phthalate plasticizer from PVC was more of a problem some years ago, not much now. The difference between the gray and the white PVC is one of ratings--such as what each is rated for pressure or for temperature. The gray PVC is rated for a higher temperature since it is used for electricity, but is not rated for pressure, even though it could probably take as much pressure as the white. The gray is also thicker, so given the same outside diameter as white PVC, the inside diameter will be smaller since the gray, being used for buried electrical, needs to be more crush-resistant. Otherwise, I wouldn't be too concerned about using the gray type for pond plumbing used for pumping water through the pond system. The type of plastic that has the most potentially volitile plasticizer is flexible tubing, as it is the plasticizer that makes the plastic soft and flexible. More danger of leaching from it, yet tubing is what we use lots of in pond plumbing. Interestingly, kids toys are made with soft plastics (and, therefore, more plasticizer). If we're concerned about leaching plasticizer, maybe we should be concerned about kids toys first.

Don

Hi Don, thanks for the info on the PVC "parts". I enjoy reading your posts as there is always something to learn from them :-) Thanks for sharing your knowledge!