PO4 Pro Test

Phosphate test professional for fresh and saltwater aquariums

Measuring range & accuracy

Measurement range for freshwater: 0.01 - 1.0 mg/l (ppm)

Measurement range for saltwater: 0.01 - 1.0 mg/l (ppm)

Accuracy: 0.02 mg/l (ppm)

About phosphate

Phosphates are important nutrients for all plants and are vital for the energy metabolism of every living cell. Phosphates are released into the aquarium water via food and the decomposition process of organic matter. However, an unregulated increase in the phosphate concentration creates problems, such as significant algae growth. In addition, phosphates in salt water aquariums can seriously inhibit the deposition of calcium carbonate in the skeleton formation process of hard corals and, in turn, for their growth. On the other hand, there can be a shortage of phosphate if there is a high stock of plants and / or corals and a low fish population. In this situation, phosphate will need to be added. Some reef aquariums are intentionally set up to have ultra-low nutrient conditions – phosphate shortages can occur in cases such as these.

In freshwater applications, a phosphate concentration of up to 0.4 mg/l (ppm) is suitable, however 1 mg/l (ppm) should not be exceeded. Even a concentration of 0.02 mg/l (ppm) is adequate for supplying aquatic plants with nutrients. The phosphate concentration in natural saltwater is approximately 0.06 mg/l (ppm).

We recommend that you prevent the concentration of phosphate from rising above 0.1 mg/l (ppm) in saltwater tanks and keep the concentration between 0.01 and 0.05 mg/l (ppm) in reef aquariums. To monitor this effectively, the phosphate concentration in the aquarium water should be tested regularly.

Package contents

25 ml / 0.85 fl.oz. of reagent A
6 ml / 0.20 fl.oz. of reagent B
5 ml / 0.17 fl.oz. of reference solution “standard”
2 glass cuvettes 20 ml
1 dosing syringe 20 ml
2 colour cards
1 comparator
1 instructions for use

Instructions for use

Shake the dropper bottles before use! Assemble and prepare the comparator.
Rinse out both glass cuvettes with tap water and then several times with aquarium water.
Fill each glass cuvette with exactly 15 ml of aquarium water using the dosing syringe. Put one of the two water samples aside as a reference.
Add 10 drops (for saltwater) or 12 drops (for freshwater) of test reagent A to the test cuvette, close the glass cuvette using the stopper and briefly shake the sample.
After that, add 3 drops of test reagent B, close the glass cuvette once again and briefly shake it.
After 4 minutes of development time place the open test cuvette and the reference cuvette with the water sample into the comparator. Place the comparator on the colour card in such a way that the reference cuvette is sitting on a coloured field and the test cuvette on a white field.
Now compare the opposing fields. To do this, look into the open cuvettes from above. Move the comparator on the colour card until both cuvettes match exactly.
Read off the phosphate concentration under the relevant colour field. If the colours do not match exactly, an intermediate value can be estimated.
Rinse out the glass cuvettes and the syringe thoroughly with tap water after the measurement process.

Using the “standard” to verify the test:

The shelf life of reagents depends on storage conditions and other factors. If the functional capacity of the test is inadequate, there will be no colour reaction during the test, even if phosphate levels are particularly high. If the measurement result is below 0.1 mg/l (ppm), add three drops of the reference solution “standard” to a new sample in order to verify the reliability of the test. If the colour changes to blue when you carry out the test again, then the reagents are verified as good.

Shelf life and storage:

6 months after opening. Store in a cool, dark place.

Measures in the event of unfavorable values

If the phosphate concentration in the water is too high, we recommend:

using the highly efficient Tropic Marin® phosphate adsorbents: Tropic Marin® Elimi-Phos, Tropic Marin® Elimi-Phos Longlife or Tropic Marin® Elimi-Phos Rapid;
using natural methods to lower the phosphate concentration such as the products Tropic Marin® Elimi-NP, NP-Bacto-Balance, NP-Bacto-Pellets or Amino-Organic
assessing and, where necessary, reducing the stocking rate and feeding quantities or enriching the food with Tropic Marin® Lipovit/ Lipo- Garlic;
removing detritus, dead plants and other dirt;
stimulating the growth of plants in freshwater tanks or caulerpa and soft coral in saltwater aquariums.

If phosphate levels are too low, we recommend (with due consideration for the nitrate concentration at the same time):

using Tropic Marin® Plus-NP as a balanced source of nutrients in saltwater aquariums;
increasing the feeding quantities.

More Tropic Marin test kits

In order to protect the environment, the reagents for the phosphate test are also available in affordable refill packs!

Frequently asked questions

Answers to frequently asked questions about this product can be found in our FAQ section.

Container sizes

PO4-Test Professional Art. Nr. 28350 Refill Pack Art. Nr. 28786