Flourish Iron is a highly concentrated (10000 mg/L),
ferrous iron (Fe+2), gluconate supplement.
It should be used in those cases where the iron
requirements exceed that which can be delivered by Flourish at the
recommended dose.
Ferrous iron gluconate is a more suitable iron supplement
for aquatic plants than is ferric (Fe+3), iron-EDTA for two reasons.
(1)Plants
require iron in the ferrous state so physiological energy must be
expended by the plant in order to extract the ferric iron from
EDTA-iron and then convert (reduce) it to the
ferrous form. Ferrous iron
gluconate is already in the ferrous form so this reduction step is not
necessary.
(2) Ferrous
gluconate is better suited to foliar feeding than is iron-EDTA owing to
the relatively weaker iron-gluconate bonding vs. iron-EDTA bonding.
Contains no phosphate or
nitrate.