Based on this product's specifications, here are some alternatives and similar models
Water test reagent sera Iron-Test (Fe) — Iron measurement, 0.015 L, hanging box
Summary description:
sera Iron-Test (Fe) is a water test reagent for measuring iron (Fe) concentration in aquaria and other water samples. Supplied in a 0.015 L volume in a hanging box, the reagent enables chemical determination of iron levels to monitor water quality. Designed for routine testing to detect iron contamination or manage nutrient dosing in aquatic systems.