Subject: How you can you simulate or obtain HNLC ocean water for iron fertilization?

Hi,
I'm doing a science fair project about iron fertilization, and my partner and I
want to show how the addition of iron to the ocean affects the growth of
phytoplankton there. We know that iron fertilization works because many of the
waters in the ocean are deficient in iron, specifically called high-nutrient
low-chlorophyll (HNLC) waters. These places have almost all of the nutrients
needed for phytoplankton to grow except iron. Iron is essential for
phytoplankton to grow, so when iron is added to the deficient areas, more
phytoplankton grows. When we grow phytoplankton for our experiment, we want to
recreate a similar environment so that the water is abundant in other nutrients
(such as nitrate, phosphate, and silica) required for phytoplankton growth, but
still deficient in iron. This way, when we add different amounts of iron to the
experimental groups, the iron will actually make a difference in the growth of
the phytoplankton. Can you help us figure out a way to simulate or obtain this
type of ocean water without actually going to the ocean? 
Thanks.

Re: How you can you simulate or obtain HNLC ocean water for iron fertilization?