() writes:

GY (Wed, 27 Aug 2003 21:56:23 GMT):
30x50 liner... that went 474 pounds each

So why not permalon and you won't have to worry about leaching at all.
And man, it's a heck of a lot lighter than that. 474 pounds... I can
roll 500 lbs, but it could roll me (flat), too. 30x20 permalon I could
pick up and toss around, easy.

Yep, weight is a problem with EPDM in bugger sizes.

Can you do the pipe boot trick with permalon?
If not you must add a few bulkhead fittings, and the big
ones cost BIG.

I've got pond gard up in the filter but the rest is permalon, factory
direct at $0.22 sq ft (1997).

http://www.reefindustries.com/
http://www.reefindustries.com/php/pondline.php

Couldn't find prices, I wonder if they insist on phone?