Phosphate test

Performance & sizing

Core numbers for matching this unit to your tank and electrical plan.

Power

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Flow rate

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Noise

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Dimensions

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Price range

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Tank fit (L)

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Consumables & maintenance

Calibrate probes and replace test reagents per kit instructions.

Description

Phosphate is the nutrient most people test for only after the algae has already won. The EPA's summary of phosphorus is written about lakes and rivers rather than aquariums, but the mechanism it describes is the one running inside a glass box. Phosphate is the form of phosphorus that living organisms actually use, and too much of it stimulates the growth of algae, which then drives dissolved oxygen down, blocks the light that plants and other organisms need, and degrades conditions for the animals living on the bottom. The line worth carrying over is about scale. The EPA notes that phosphorus generally occurs in small quantities in the natural environment, so even small increases can affect water quality and biological condition. That is why a phosphate reading behaves differently from an ammonia reading. Ammonia is a fast poison. Phosphate is a slow input whose effect shows up in what grows rather than in what dies. In a tank the sources are easy to list and easy to overlook: uneaten food, waste, some tap water supplies, and fertiliser dosed for the plants. A reading that climbs month over month usually points at feeding, or at a water change schedule that has quietly slipped, and the value of a test kit is that it turns that into a number before it turns into green glass. One honest gap. No authority found here publishes a target phosphate concentration for a planted aquarium. The EPA page gives no milligram per litre figure of any kind, and the ideal ranges passed around hobby forums have no source behind them that this catalog can point at. Use the kit to watch the trend in your own tank, which is a comparison you can defend, rather than to chase somebody else's number.

Source

• epa.gov — https://www.epa.gov/national-aquatic-resource-surveys/indicators-phosphorus

Figures on this page were read off these pages. Manufacturers and databases do change or retire pages; if a link is dead, tell us with the correction link below.