The JBL PROAQUATEST Mg Magnesium Freshwater is an essential liquid test kit designed to accurately measure magnesium (Mg) concentrations in freshwater and planted aquariums. Magnesium acts as a crucial macroelement that directly influences chlorophyll production and overall aquatic plant vitality.

Note for Beginner Aquarists: Managing magnesium levels is a wonderful step up for hobbyists diving into advanced planted tanks. If your aquatic plants are showing signs of stunted growth or yellowing leaves despite regular dosing, tracking your magnesium levels with this precise kit will help you dial in a perfectly balanced fertilizer routine.

Short Description & Highlights

The JBL Magnesium Test Kit provides a reliable, laboratory-grade colorimetric method to monitor magnesium levels ranging from 0 to over 10 mg/l. Featuring a specialized comparator block system that neutralizes background water coloration, it ensures clear and repeatable results. Each kit comes equipped with reagents for approximately 60 measurements, a dosing syringe, and easy-to-read color charts, making professional water analysis accessible for beginners.

Key Product Highlights:

Detailed Beginner Care Guide

1. Understanding Magnesium in the Aquarium

Magnesium works alongside calcium and potassium to regulate plant metabolism and nutrient uptake. In soft water setups or heavily planted Dutch aquariums, magnesium can easily become depleted, leading to poor plant health. Regular testing helps you identify deficiencies before they impact your scaping layout.

2. Step-by-Step Testing Process

Rinse the provided glass sample vials thoroughly with the aquarium water you intend to test. Use the enclosed syringe to measure exactly 5 ml of water into each vial. Add the specified drops of reagents sequentially following the detailed instruction manual, cap the vials, and gently mix.

3. Reading Results with the Comparator

Place the vials into the smart plastic comparator block—one slot on the blank side and one on the test side—to neutralize any inherent yellow-brown tint or discoloration in your aquarium water. Slide the block across the color chart until the colors match identically, allowing you to read your precise magnesium value with confidence.