Is grey PVC considered reef safe?
 

Is grey PVC considered reef safe?

I know its still PVC and compatible with the white. Its for electrical conduit and white is approved for potable water sittuations. Its nice because its schedule 40, (thinker then the white).

I want to use it for my return lines. I think it looks a little better then plain white with primer/glue stains!

Thanks for any input!

Good question. I don't really know myself, but, another thought is that schedule-80 is also grey, a lot of people use it for the looks, so that's an option for you as well. It's for much higher pressure so it's even thicker (other than looks it's total overkill for an aquarium).

I've used it before. I think you should be fine.

i used it too and it is fine. Just make sure you let it dry for 24 hours or so to be safe

Keep in mind that the thicker walled material, such as Sched 80, will restrict flow more than equivalent sized Sched 40. Outer diameter is the same, but inner is less to allow for thicker wall = more restriction/less flow. Solution is, of course, to upsize when going to thicker walled material.