FAQ: When I add Seachem Flourish Iron™ to my tank within a couple minutes it gets very cloudy

 A: A: This is a peculiar response. Flourish Iron™ does not normally cause cloudiness unless used excessively, and even then the cloudiness is very mild. Since the cloudiness was caused by a white precipitate, as you confirmed by testing, it is not an iron precipitate. It is also unlikely to be a direct carbonate precipitate. I suspect that your water is exceptionally hard (contains a lot of calcium/magnesium) and that you may also have a high alkalinity (carbonate content), and that the addition of Flourish Iron™ (by an ion competing mechanism) pushes the calcium/magnesium carbonate in the water beyond saturation, resulting in the precipitation of calcium/magnesium carbonates. Even without the addition of Flourish Iron™, do you sometimes see a white (chalky) film on the surface of the water? If so, that would support the presence of high calcium/magnesium. You may want to test your water for calcium/magnesium and alkalinity. If you experience problems growing certain plants, that may also suggest excessive hardness, since many plants prefer soft to only mildly hard water. Do you see any cloudiness when adding bicarbonate? If you have to frequently add bicarbonate, you may be using to much CO2. Regardless, however, I expect your calcium/magnesium hardness is the culprit. While this is nothing to panic about, if it should prove to be the case, I think you would do better to dilute out your water with some kind of soft water, such as DI, RO, or rain water.