How Wavie works

Wavie measures water in two ways.

• Probes sit in the tank water and are read continuously: pH, ORP, salinity, temperature and, with the add-on probe, dissolved oxygen.
• Reagent tests run on a schedule. Wavie draws a small sample, adds a reagent, and measures the colour that develops. These give alkalinity, calcium, magnesium, nitrate and phosphate.

One reagent test, step by step

1. Home the valve. The rotary valve finds its home switch so it knows exactly which port it is on.
2. Draw the sample. The valve turns to the sample port and the pump pulls a measured volume of tank water into the cell.
3. Take a reference reading. With plain sample in the cell, the photometer records how much light passes through at the wavelength the test uses.
4. Add reagent. The valve turns to a reagent port and the pump meters in a precise dose. A small fan-driven stirrer mixes the cell.
5. Read the colour. One LED shines through the cell onto a light sensor. The drop in light compared with the reference is the absorbance, and absorbance becomes a concentration.
6. Flush. The valve turns to waste, the pump empties the cell and rinses it with fresh sample, ready for the next test.

Everything shares one fluid path: one pump, one valve, one cell. That is what lets the instrument be so small.

Which method each parameter uses

Parameter	Method
Alkalinity, calcium, magnesium	Titration: sample and reagent are combined in small steps until the colour changes. Calcium and magnesium share a single hardness measurement.
Nitrate, phosphate	Colour development: a reagent turns the sample a colour whose depth depends on the concentration.
pH, ORP, dissolved oxygen	Electrode probes on isolated inputs.
Salinity	Conductivity probe, converted to salinity.
Temperature	Digital temperature probe; also used to correct the other probes.

The reagent chemistry is still in development. See Reagents.