FYI

I posted this thread after killing a strain of WW I had been enjoying for almost three years.

This was the result of "upgrading" the air delivery via a manifold made of 1/2" copper.

The cause of the loss was confirmed by the fertilizer supplier (GH) and several other sources.

The reason I posted this information was to help anyone else, as information on "banned" building materials for hydroponics is not easy to find.

In short, DO NOT USE COPPER FOR NUTRIENT DELIVERY OR AIR DELIVERY (if the copper is gonna be exposed to the soup).