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Red Sea Phosphate Pro Test Kit
Red Sea Phosphate Pro Test Kit

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* Colorimetric aquarium test kit for accurate and easy-to-read results
* Color wheel comparator simplifies the testing of aquarium phosphate
* Versatile test kit with results for high and low range phosphate levels

Accurate colorimetric (color matching) phosphate testing is as easy as turning a color wheel. Red Sea Phosphate Pro Test Kit takes an innovative new approach to boost accuracy of colorimetric phosphate testing. Traditional colorimetric tests involve matching sample water against a small, difficult to match color chart or color chip. Easy-view Red Sea Phosphate Pro Test Kit comparator secures the sample vial against a white background and you simply rotate the color wheel until there's a match. Comparator is viewed from above to eliminate fumbling or awkward handling of test vial and color chart.

Red Sea Phosphate Pro Test Kit boasts a new level of convenience for reef aquarium hobbyists. Routine and precise measurement of aquarium phosphate levels is essential for monitoring unwanted algae growth in coral reef aquariums. High levels of phosphate can not only fuel unwanted algae growth but can also affect coral growth and coloration. This advanced colorimetric phosphate test kit encourages proper testing skills with ease-of-use and a high degree of accuracy (0.014ppm).

Included quick guide walks you through the testing process with simple, easy-to-understand illustrations. Colorimetric chart displays phosphate test results from 0.014 to 1.6ppm. Measure and monitor phosphate levels with Red Sea Phosphate Pro Test Kit to ensure ideal water parameters for coral reef aquariums housing SPS, LPS and Soft Corals. 100 Tests. Accuracy of 0.014ppm.


  • Comparator
  • Instruction Manual
  • Color Disc
  • Syringe 10ml
  • Reagent A - 50ml
  • Reagent B - 15ml

Directions for Phosphate Pro Test Kit

  1. Using the syringe provided, place exactly 17 ml of the water to be tested into both of the glass vials.
  2. Insert one of the vials (control vial) into the outer hole of the Comparator.
  3. Add 10 drops of Phosphate Pro Reagent A to the other vial (reaction vial), close the vial with the cap and shake for a few seconds.
  4. Add 2 drops of Phosphate Pro Reagent B, close the vial with the cap and shake for a few seconds.
  5. Remove the cap from the reaction vial and insert the vial into the center hole of the Comparator.
  6. Wait 6 minutes for the color in the reaction vial to stabilize.
  7. When the end point of the test reaction has been reached, look into both vials from above and rotate the color disc until the closest color match possible is achieved between the vials. Note: Turbidity or severe coloration of the water sample may distort the colors.
  8. The phosphate level corresponding to the color selected is printed on the color disc as indicated by the pointer on the side of the comparator body. If necessary, estimate an intermediate value.
  9. The color in the reaction vial will remain stable for 5 minutes. Do not relate to the color in the reaction vial after this time.

High Range: For levels of phosphate above 1 ppm, dilute 2ml of the water to be tested with 15ml of RO water.

General Information
Important notes for using the Colorimetric Comparator Test Kits

  • Before testing, clean the glass vials and the large syringe by rinsing with the water to be tested.
  • After testing, rinse all syringes and vials with RO or distilled water before storing. If vials are left unwashed, a residue can form that will affect the results of future tests. Use a slightly acidic solution such as vinegar to remove the residue.
  • Close all reagents tightly immediately after use.
  • The test reagents are stable up to the date stated on the pack when stored closed between 15 - 25°C (59 - 77°F).
  • Store the reagents and color card in the plastic box to prevent damage from prolonged exposure to light.

P-PO4: Table below gives the values for P-PO4 the Phosphorus content of Phosphate.

Low range
PO4 0.02 0.04 0.08 0.16 0.36 0.64
P-PO4 0.007 0.013 0.027 0.053 0.120 0.213

High range
PO4 0.17 0.34 0.68 1.36 3.06 5.44
P-PO4 0.06 0.11 0.23 0.45 1.02 1.81

Assembling the Colorimetric Comparator

  • Press the catch in the recess of the base outwards and raise the body of the Comparator from the base.
  • Place the color disc onto the base so that the white surface on the base is in the center of the disc.
  • Replace the body of the Comparator by hinging it to the base at the back and pushing the catch through the center of the disc. The color disc should rotate freely in the Comparator. NOTE: In order to maintain the high accuracy of Red Sea's colorimetric comparator Pro Tests, they are supplied with special optically clear glass vials that have a slightly smaller diameter than the regular glass vials supplied with all other kits. To prevent mistakes, the regular glass vials do not fit in the Comparator.

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