[Dutchie]

Hello,
I am dosing Seachem Flourish Excel in a moderately planted tank. It is said that one should maintain Fe2+ levels at 0.10 mg/l. If I dose 10 ml of Seachem Iron in a 180 l tank after the lights turn off, iron levels are 0.5 mg/l. I know, this is way too high. However, the next morning, before the lights turn on, the iron level has dropped to 0.05 mg/l. Needless to say that at the end of the day (24 hrs after dosing Seachem Iron...and probably way before that), the iron levels are 0. I can imagine what would happen if I would dose seachem iron as adviced by its manufacturer. So how to maintain 0.10 mg/l? Is it normal that iron levels during complete darkness drop from 0.5 to 0.05 mg/l? Are plants using iron when there is no photosynthesis? Or is the iron just very instable? Or does is get reduced into Fe3+? Would it be best to dose seachem iron in the morning? Thanks in advance.

 

[Zorfox]

Iron isn't very stable. This is the reason chelates are added. I believe Flourish iron uses Ferrous Gluconate. That's a non chelated form of iron so it won't last very long. It is however more easily utilized by plants. A combination of Ferrous Gluconate, EDTA iron and DTPA iron would be beneficial. Ideally, using three forms of iron would provide benefits of short term and long term availability. Even with this method the iron will only last around 48 hours depending on PH.

If using Flourish iron I would dose in the morning since the iron will most likely not last the entire day. Btw, 0.5 ppm is not too high. That's the suggested dose for the EI method .

 

[Dutchie]

Thanks Zorfox

For your (or anybody's) info, the next message is a reply that I got from Seachem. Maybe Propel may be a good (or better) alternative

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Hello Roland,

the iron that is in Flourish Iron is a Ferrous Gluconate form of iron, and as such is very bio-available. The scenario that you have outlined below is something that is very common with the product. Plants are using iron when there is no photosynthesis as it is a key component in chlorophyll production. To remedy this problem we have release Propel in the Aquavitro plant line. Propel still contains the bioavailable and preferred Ferrous Gluconate, but also contains a time-release iron, as well as a product that will convert existing Ferric iron into Ferrous iron which is the preferred form of iron for plants. Propel is a product that, because of the time-release iron, is much easier to test for, and therefore dose appropriately.

I hope this helps!
Cheers~!
Seachem Tech Support JG012681

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