Iodine is present in natural sea water in a very low concentration (0.6 mg/L or 0.06 ppm) and this iodine occurs as several different species including iodide, iodate, molecular iodine and hypoiodite. • There is a misconception among many hobbyists that iodide predominates in natural sea water but in fact, it is iodate which is the predominant element. • Test kits which are not capable of detecting iodate are not suitable for aquarium use, since in a properly functioning tank most of the iodide will be transferred to iodate and any test kits not able to detect iodate will give a false, low iodine reading. • Iodine test kits should be capable of measuring all forms of naturally occurring iodine. The Salifert Test Kit is the only one offering this feature, measuring all naturally occurring iodine compounds and giving a reading of total iodine concentration. • Unlike many other test kits, the Salifert Iodine Profi-Test is free from interference from other elements found in saltwater, which means the results obtained are very accurate. • Colour remains stable for several hours. • Scale goes from 0.01 - 0.15ppm and optimum level is 0.06 mg/L. • Salifert Natural Iodine 250ml is highly concentrated and contains a large proportion of iodate and some iodide in the same balance as natural sea water. • Can provide up to 40 tests