On Mon, 15 Dec 2003 23:40:24 -0500, Ben wrote:
tank. Now here is the thing, the house I live in was built in 1923 and
has old iron pipes. Now is there going to be enough trace iron in the
water or am I going to have to add it. just wondering

Iron in the form of rust won't be easily absorbed by the plants. The
roots might be able to get to rust in the substrate, but the leaves
won't be able to take it up.

That's the reason fertilizers contain "chelated" iron. It's iron in a
form easily utilized by plants.

Chuck Gadd
http://www.csd.net/~cgadd/aqua