Shagster wrote:
I guess my REAL question was... Will activated carbon filter out plant
fertilizers like Iron supplements?

Troy

Yes, but nothing a bit of extra dosing can't fix, especially if you dose
daily. I've been running one of my planted tanks with carbon because a
new piece of mopani wood has been turning the water brown. The plants
are growing fine.

I test all of my tanks for iron, and the ones where I'm using carbon for
whatever reason usually need more iron/trace element fertilizer. Carbon
should leave the potash, phosphate, and nitrate in the water so no need
to change those.

BTW, be careful to buy good carbon. Some brands are treated with
phosphoric acid and have a LOT of residual phosphate in them. If you're
not sure, set up a phosphate test with distilled water and drop some
carbon into the test tube.

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com