The Laborett consists of liquid test reagents, which alter the colour of the sample water to reflect the concentration of the various parameters. The carbon dioxide content is worked out from the levels of KH and pH. How to Use
For all: 1. fill the vial to the 5ml mark.
for pH: 2. hold the pH bottle upside down and add 7 drops to the vial; 3. close and shake the vial; 4. compare the colour to the chart.
for GH and KH: 2. hold the reagent upside down and add 1 drop to the vial, and shake; 3. Continue to add drops until the liquid changes colour (for GH, from red to green, for KH from blue to yellow); 4. The number of drops it takes to change the colour of the liquid equals the GH or KH in °dH.
for nitrite: 2. hold nitrite reagent bottle number 1 upside down and add 7 drops, close vial and shake gently; 3. After 10 seconds add 7 drops of nitrite reagent number 2, close vial and shake gently; 4. Leave vial to stand for 2 to 5 minutes for full colour.
for CO2: read value from chart of pH/KH.