Aquaforest. AF Iron, 50 ml.
Dosage: 1 drop per 100 liters (27 US gal) daily.
Recommended level of iron in reef aquariums is 0,006– 0,012 mg/l (ppm).
1 ml of Iron (~15 drops) in 100 l (27 US gal) raises the iron level in water by 0.005 ppm = 5 μg/l. It is important that each aquarium is different and the dosage depends on the coral cast and individual needs. Do not overtighten the screw, otherwise the cover might be damaged.