On Sat, 25 May 2013 08:19:11 +0000, Danny D. wrote:

This listing also mentions pool o-ring material; but it is confusing at best.
http://tinyurl.com/nojnt73
http://www.theoringstore.com/index.p...ducts_id=18551

24850-0009 Sta-Rite Tank O-Ring - System 3 Filter, 25 inch diameter
Alladin O-486
The o-rings listed are made from Buna, Viton or EPDM compounds.
All pool o-rings are made from Buna unless otherwise stated.
If you are running a chlorine system and can not locate the Viton o-ring
that you need, please contact us to make sure one is available.

From that, I can't tell if pool o-rings are buna or viton.