Description

For perfect aquarium plant growth: determines the ideal magnesium value to monitor the fertilisation of freshwater aquariums
Laboratory comparator system to compensate the inherent water colour: fill glass vials with sample water, add reagents to one vial, place vials in holder, read values off colour chart
Magnesium deficiency in aquatic plants leads to stagnant growth and light leaf colour. Remedy: Increase magnesium-containing fertiliser: JBL Ferropol, JBL ProScape Mg Macroelements
You will find detailed information and troubleshooting tips about water analysis on the JBL website in Essentials/Aquarium or Pond
Package contents: 1 Mg test kit for approx. 60 measurements, incl. 3 reagents, 2 glass vials with screw caps, syringe, comparator block and colour scale. Reagent refill separately available

Healthy aquariums with conditions close to nature
The right water values are dependent on the fish stock and the plants in the aquarium. Even if the water looks clear it can be contaminated. With bad values diseases or algae can appear in the aquarium. To maintain a healthy aquarium with conditions close to nature it is important to check and adapt the water values regularly.

For each water analysis JBL provides water tests in the form of rapid tests or colour change tests. These determine a certain value or several values in one go. With these water tests you can recognise algae problems and negative nitrate, nitrite, potassium, magnesium values etc.

Why test?
Along with calcium, magnesium creates the general hardness. Magnesium is, like potassium, a macro-element, which is necessary for healthy and vigorous growth in plants. Tap water very often contains too low quantities of magnesium for aquatic plants, quickly causing deficiency symptoms. Even if you fertilise the aquarium water regularly, there may still be too low quantities of magnesium available and the plant growth will then stagnate.

Recommended magnesium values:
Freshwater aquarium (community aquarium): 5-10 mg/l
Lake Malawi/Lake Tanganyika aquarium: 5-10 mg/l
Plant aquarium with few fish (aquascaping): 5-10 mg/l
Marine water aquarium: this test is not suitable since the magnesium content in marine water lies at 1200-1600 mg/l. Therefore for marine water use the dedicated JBL Magnesium/Calcium Test.

You can analyse the water values you have measured in the JBL Online Laboratory free of charge and receive recommendations

Why Singapore aquascapers reach for the JBL Mg test kit

Singapore tap water is soft and slightly acidic, which is wonderful for many plants but means magnesium often sits lower than your stems and carpets would like. Without enough Mg, leaves pale between the veins and growth stalls even when everything else looks dialled in. This freshwater comparator kit lets you read the actual value rather than guess, so you can dose to a target instead of pouring in fertiliser blindly and feeding algae.

We recommend testing a fresh sample before and a day after a water change, since our tap supply shifts a little through the year. The glass-vial comparator cancels out any tint already in your tank water, giving a cleaner reading than strip tests. Most planted community and aquascaping setups here run comfortably in the single-digit mg/l range, and once you know your number you can keep it steady with a magnesium-specific top-up rather than over-dosing general fertiliser.

Find this alongside our other kits in water testing & care. Pair your readings with our magnesium deficiency guide, our calcium and magnesium balance guide, and the local context in our Singapore water hardness map.