we tried someting new

I remember someone else saying they witnessed rolls of Firestone epdm coming
from the same source and seeing some of it stamped, or labelled as being
pond-grade and the rest of it marked for roofing only.
"Gale Pearce" wrote in message
...
Firestone said themselves there is a difference in the "curing "process -
ergo not fish safe - this was posted a while back on this group - if you
want I will see if I can find the letter and repost it if you can't find
it
and yes I know many people have used roofing epdm without a problem
Gale :~)

"Derek Broughton" wrote in message
...
Benign Vanilla wrote:


"Derek Broughton" wrote in message
...
snip
The old-timers here will remember that, at the time I started into
ponding,
sometime in the mid-90s, one of the hottest debates was over the use
of
pond-safe EPDM and EPDM roofing liner. Firestone, the major
manufacturer
of both, insisted that the roofing liner was not fish-safe, but many
people
used it without trouble. I know of one DIY study that claimed it
killed
test fish, but I also know of dozens of respected ponders who never
had
a
problem.
snip

The key variable here is that in some areas, roofing liner can be
treated
for fungus, mildew, etc. and those chemicals could be harmful to fish.
My
EPDM was purchased from a pond store, and it says Firestone on it. So
I
guess my area does not have these "mythical" chemicals.

That was part of the discussion, but while a number of _roofers_ claimed
it
was treated with fungicides, nobody connected with Firestone ever said
that. So, yes, they seem to be mythical. But I still wouldn't risk a
hundred dollar koi in a pond made with roofing liner. The stuff you got
was almost certainly pond-grade, though. Firestone does sell pond-grade
epdm, and it doesn't come from the same supply as roofing-grade epdm -
but
whether there's any chemical difference, nobody really knows.
--
derek