Aquarium and pond equipment at the best prices!
For those passionate about aquariophily
Having trouble finalizing your order? Contact us 24 hours a day by email at information@zoanthus.fr.
Basin Analysis
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)
Balling Products
Seawater supplements
Basic elements
Fresh Water Supplements
CO2 system
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)
Water treatment
Bacterial Treatments
Adverse Treatments
Fish Care
Water treatment
Bacterial Treatments
Adverse Treatments
Fish Care
Water treatment
Bacterial Treatments
Fish Care
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)
Sand
Substrate for reactor
Sea Salts
Pond Substrate
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)
Seawater Equipment
Basin Equipment
5€ discount for your first order with the code: BIENVENUE05 (from 100€ purchase, offers cannot be combined)


Zoanthus Lab Calcium 1000 ml is a concentrated solution designed to precisely correct calcium deficiencies in marine aquariums. A central element in reef balance, calcium (Ca) is essential for the growth of hard corals, giant clams, calcareous algae, and many other reef-building organisms. Formulated with purified water and pharmaceutical-grade calcium chloride dihydrate , this supplement offers a clear, stable, and perfectly measurable concentration. Free from unnecessary additives and complexing agents, it integrates seamlessly into a rigorous management system based on ICP analysis. A reliable, transparent solution designed for discerning aquarists.
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Magnesium + Zoanthus Lab 1000 ml is a concentrated solution designed to precisely correct magnesium deficiencies in marine aquariums. Essential for the chemical stability of seawater, magnesium (Mg) contributes to overall ionic balance and helps maintain a proper ratio of calcium, KH, and salinity. Formulated with purified water , pharmaceutical-grade magnesium chloride hexahydrate , and pharmaceutical-grade magnesium sulfate heptahydrate , this product guarantees a clear, stable, and perfectly measurable concentration. Free of unnecessary additives and complexing agents, it integrates perfectly into a rigorous management system based on ICP analysis. A reliable, transparent solution designed for discerning aquarists.


KH + Zoanthus Lab 1000 ml is a concentrated solution designed to precisely correct alkalinity in marine aquariums. KH is a fundamental parameter for reef balance, directly linked to pH stability and the proper functioning of calcification processes in hard corals, calcareous algae, and other reef-building organisms. Formulated with purified water , pharmaceutical-grade sodium carbonate , and pharmaceutical-grade sodium bicarbonate , this product guarantees a clear, stable, and perfectly measurable solution. Free of unnecessary additives, it is ideally suited for rigorous management based on ICP analysis. A reliable, transparent solution designed for discerning aquarists.


Zoanthus Lab Phosphate Minus 1000 ml is a concentrated solution designed to precisely reduce excess phosphates in marine aquariums. Phosphates ( PO4 ) are essential nutrients in small doses, but their accumulation can hinder calcification, promote biological imbalances, and complicate the maintenance of a stable reef tank. Formulated with purified water and pharmaceutical-grade iron(III) chloride , this product guarantees clear, stable, and perfectly measurable action. Free of unnecessary additives, it integrates perfectly into a rigorous management system based on ICP analysis. A reliable, transparent solution designed for discerning aquarists.
Calcium is one of the major elements in seawater . It plays a fundamental role in building the skeleton of hard corals (SPS and LPS), calcareous algae, giant clams, and other calcifying organisms. In a reef aquarium, it is one of the most important parameters to monitor to maintain steady growth and a stable environment.
Calcium consumption is continuous in an active reef tank. It increases with coral density, biological growth, and the intensity of calcification. A gradual decrease can hinder growth, limit calcification, and disrupt the overall stability of the tank if not properly corrected.
We offer a full range of products to target the main elements of seawater following ICP analysis or manual testing.

The Zoanthus Lab – Calcium solution is prepared from calcium chloride dihydrate (CaCl 2 ·2H 2 O) , dissolved in purified water.
The formula is based on rigorously selected raw materials, including pharmaceutical-grade calcium chloride dihydrate , to guarantee a pure, homogeneous solution suitable for precise reef supplementation. This choice ensures excellent readability of ICP analysis results and perfectly measurable correction.
The solution is formulated according to a precise protocol:
Supplementation should always be based on a recent ICP analysis or reliable measurements. In case of a significant [oaicite:1] , it is recommended to split the correction over several days to preserve the chemical stability of the tank. The preparation protocol also indicates a practical dosage formula: tank volume (L) × target increase (mg/L) {index=1} 200.
Each Zoanthus Lab product can be controlled via our free Zoa Aqua Manager calculator. In just a few seconds, you get a precise and personalized dosage from your ICP analysis (Zoanthus Labs or any other laboratory).
No more manual calculations: enter your water volume, your measured value and your objective, and the system automatically calculates the appropriate correction, with the possibility of progressive dosing for optimal stability.
A tool designed by aquarists, for demanding aquarists.

The essentials for reef aquariums
Complete analysis of the major elements and trace elements essential for the regular monitoring of your reef aquarium.
Ultra-comprehensive diagnosis
In-depth reading with expanded spectrum including fluoride, nitrates, KH and reverse osmosis water analysis.
Special reverse osmosis water
Precise control of your preparation water to ensure a perfectly healthy base before any remineralization.
The results of each analysis can be directly used in our free Zoa Aqua Manager calculator for precise and personalized dosing.

Add to a well-circulated area of the aquarium or to the sump. Shake well before use.
Store away from light, between 15 and 25°C. Keep the container tightly [oaicite:2] and protected from moisture. The protocol also recommends using opaque {index=2} airtight containers to preserve the stability of the solution.
As with any major element, excessive supplementation is counterproductive and can disrupt the tank's chemistry. Regular monitoring via ICP analysis remains the most reliable method for adjusting calcium levels sustainably and safely.