when you get iron, see if you can get it as Fe++ (ferrous iron) vs. Fe+++ (ferric iron). plants can only absorb iron as Fe++; they have a mechanism to convert Fe+++ to Fe++, but the more they have in the already available state the better. unfortunately our tanks are acidic and so iron, while more soluble, is more likely to be in the ferric state than ferrous state. but since you would be dosing several doses a week, there should be ample burst of nicely available Fe++ complexes in the water.
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