Flourish Iron^™

•  Highly concentrated (10,000 mg/L)
•  Ferrous gluconate iron
•  Ferrous gluconate is better suited to foliar feeding than iron-EDTA

Description

Iron is immobile in plants. This means that plants cannot  divert iron from older leaves to new ones. Therefore, deficiency  symptoms appear first on new or young leaves. Because plants use iron to  produce chlorophyll, a lack of iron results in chlorosis, or yellowing,  of the younger leaves. Stems may also appear short and slender. If the  deficiency is severe and prolonged, each new leaf emerges lighter in  color than the preceding leaf.

When choosing an iron supplement, it is important to know  the distinction between the two forms of iron. The iron will be in one  of two oxidation states: ferrous having a +2 charge, or ferric having a  +3 charge. Ferrous iron, the preferred iron form and is soluble in water  at any pH. Ferric iron, however, is only soluble below a pH of around  5.5; but if the pH is higher than 5.5, which more than likely it will be  in a planted aquarium, the ferric iron will become insoluble and  precipitate, settling in the root zone. Once this occurs, foliar  absorbtion becomes impossible.

To overcome this precipitation, competing products employ  a chelate of ferric iron: iron-EDTA. While this does keep it soluble,  it has a couple of drawbacks with respect to foliar uptake of iron. (1)  Iron-EDTA bonding is very strong, thus very little of the iron will be  available to the plants over a given time frame and (2) 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. Our  approach is different in that we use a complex (not chelate) of ferrous  iron in Flourish Iron™.

Flourish Iron™ is a highly concentrated (10,000 mg/L)  ferrous iron gluconate supplement. Plants are able to much more easily  derive a benefit from Flourish Iron™ because ferrous iron gluconate is  already in the ferrous form so they do not expend energy reducing it.  Despite what other manufacturers may intimate, gluconate is not harmful  to plants or fish. In fact, ferrous gluconate is better suited to foliar  feeding than is iron-EDTA owing to the relatively weaker iron-gluconate  bonding vs. iron-EDTA bonding. In addition, ferrous gluconate has the  added bonus of being a source of carbon.

Directions

Use 1 capful (5 mL) for each 200 L (50 gallons) or as  required to maintain about 0.10 mg/L iron. For smaller doses please note  that each cap thread is about 1 mL. Use MultiTest®: Iron test kit to  monitor iron concentrations. Due to rapid utilization, test within 30  minutes. Use as needed to combat signs of iron deficiency (usually seen  in new growth) which include: chlorosis (yellowing) of tissue between  veins and short and slender stems.