the only time i run into foam core abs is at home depot. been plumbing for 9 years and never used the stuff, im not saying its inferior but just not common to my trade, atleast in my area. go to a plumbing supply house and they should have full abs pipe, or try other hardware stores. if the pipe has a white core it will proboably float.Trippingpara;2068113; said:Sounds like you have ABS pipe (which is black) not PVC pipe. The ABS pipe is two very thin layers of plastic molded over foam - hence the floating. Most people that I know with "black" pvc have white pvc that they painted black with Kyron Fusion spray paint which is supposed to be fish safe.
I think that this is one of the self-perpetuating myths that has no basis in actual experience.stevietennis;2068728; said:From what I heard ABS pipes can leak chems into your tank. I don't know if it is true or not but that fact that there is some possibility of it happening keeps me away from them. Good luck.