Fauna Marin AquaHomeTest PO4 is a professional-grade colorimetric test kit designed specifically for the high-precision determination of orthophosphate (PO43) levels in reef aquariums. In a closed marine system, phosphate management is one of the most critical aspects of husbandry; while it is a necessary nutrient, excessive levels can inhibit coral calcification and fuel the growth of nuisance algae. The AquaHomeTest PO4 is engineered to detect even minute concentrations in the ultra-low range, providing the accuracy required to maintain the delicate balance of a successful stony coral reef.
This test kit bridges the gap between standard hobbyist tests and expensive laboratory equipment by focusing on the low-range resolution.
Ultra-Low Range Sensitivity: Features a high-resolution color scale starting as low as 0.01 mg/L, allowing aquarists to monitor phosphate in the precise "sweet spot" for SPS corals.
Optimized Color Comparison: Uses a comparator block system that compensates for the natural slight tint of aquarium water, ensuring a more accurate color match against the provided chart.
Marine Calibration: Specifically developed for the complex chemistry of seawater to prevent interference from other ions like silicon or arsenic.
Large Sample Volume: Designed for approximately 50 tests, providing consistent monitoring for several months of reef maintenance.
Professional Equipment: Includes high-quality glass vials and precision syringes to ensure sample volumes are exact every time you test.
| Parameter | Recommended Value |
| Optimal Reef Range | 0.02 – 0.05 mg/L |
| Test Resolution | 0.01 / 0.02 / 0.05 / 0.1 / 0.2 / 0.4 / 0.6 / 1.0 mg/L |
| Test Method | Colorimetric (VRP Method) |
| Application | Marine / Saltwater only |
Why is phosphate testing so important?
Phosphate acts as a calcification inhibitor. If levels rise too high, corals struggle to build their skeletons. Conversely, "zero" phosphate can lead to coral starvation and tissue loss. This kit helps you stay within the ideal safe zone.
What is the best time to test for PO4?
For consistency, test at the same time of day—ideally before feeding. Feeding fish can cause temporary spikes in phosphate that may not reflect your system's baseline level.
How do I read the color chart accurately?
Always view the color match under natural daylight or a high-CRI light source (approx. 6500K). Looking at the chart under blue-heavy reef lighting will make the colors difficult to distinguish.
My test shows 0.00, but I have algae. Why?
This is known as a "false low." Nuisance algae may be consuming the phosphate as quickly as it is produced. In this case, use the test result as a guide while also managing the physical organic load in the tank.
Fauna Marin Multi Reference: The essential laboratory standard to verify that your Phosphate test reagents are still accurate and providing correct results.
Fauna Marin Ultra Phos: A high-capacity aluminium-based adsorber to quickly lower phosphate levels if they exceed your target range.
Fauna Marin Bacto Therapy: Beneficial bacteria that help consume organic waste before it breaks down into inorganic phosphate.
