If the OP and I are talking about the same thing, it's not hops. The color is wrong. More of a blue green color. Not a hops green color.
Blichmann plate chillers are made from 316 stainless, not copper. Unless you are using copper or brass fittings and soaking them with the chiller ,there are no copper salts to worry about. I see this all the time with my chiller. It's from the hops. Soak it, bake it, whatever you need to do to get it clean, then the green will go away.
from their website
the brazed part is what I am worried about. I know they are a beast and a couple hours in pbw shouldn't matter but was just wondering if anyone else had seen the same thing... thanks for all of the help and thoughts
The Therminator is the fastest way to chill your wort to yeast pitching temperature and get your fermentation off to a quick, bacteria-free start.
All 316 stainless steel plates and fittings.
Chill like the pros, as the Therminator is identical to commercial brewery chillers.
Brazed together with pure copper in an oxygen-free furnace, with no potential leaks like a gasketed unit!
Chill 10 gallons in 5 minutes to 68°F using 58°F cooling water at 5 gallons per minute (gpm).
Great for southern climates! (See notes on FAQ tab.)
Ultra compact (7.5" W, 4" D, 3" H)
Super-low restriction is ideal for gravity feed.
Easy to clean and sanitize, small enough to boil!*
Garden-hose thread connections on the water side means no extra adapters to buy!
1/2" male NPT fittings on wort side mates up with virtually all common hose-connector types, and they're easier to sanitize than female fittings!