The role of cobalt in marine aquariums
Cobalt is a trace element naturally present in seawater. It is involved in several enzymatic and microbiological processes, especially within bacteria and micro-organisms.
In modern reef aquariums, cobalt can gradually decrease due to protein skimming, less frequent water changes or biological export. Reasoned supplementation helps maintain values consistent with ICP references.
We offer a complete range of products designed to target the main seawater elements after an ICP analysis or manual testing.
A deliberately simple and controlled formulation
Zoanthus – Cobalt is prepared from cobalt(II) chloride hexahydrate (CoCl2·6H2O), dissolved in purified water.
No chelator or stabiliser is added. Cobalt is naturally soluble at these concentrations and does not require artificial complexation. This provides better reproducibility of ICP results and avoids unpredictable effects linked to chelated forms.
- ✔ Stable inorganic solution
- ✔ Chelator-free
- ✔ Compatible with all reef methods
- ✔ Clear and reliable ICP reading
Concentration and dosing
The solution is formulated for simple and precise dosing:
- Concentration: 0.4 mg/mL cobalt (elemental Co)
- Recommended dose: 1 mL per 100 L of water
- Effect: +4 µg/L cobalt
- Dosing limit: Do not increase cobalt by more than 1 µg/L per day.
Supplementation should always be based on a recent ICP analysis. For larger corrections, split the dose over several days to avoid sudden changes.
Zoa Aqua Manager: your smart dosing assistant
Each Zoanthus Lab product can be managed with our free calculator, Zoa Aqua Manager. In seconds, you get a precise and personalised dose from your ICP analysis.
No more manual calculations: enter your water volume, measured value and target, and the system automatically calculates the appropriate correction, with progressive dosing if needed.
Three ICP analyses for every need
ICP REEF, ICP MAX and ICP PURA help you monitor major elements, trace elements and, when required, RO/DI water. Results can be used directly in Zoa Aqua Manager for precise and personalised dosing.
Use and storage advice
Dose preferably in a well-circulated area of the aquarium. Store away from light at room temperature (15–25 °C).
As with all trace elements, excessive supplementation is unnecessary and counterproductive. Regular ICP monitoring remains the best way to ensure long-term stability.
