Drop Checker Instructions

Insert the dropper bottle into the drop checker and inject checker solution into the bulb until it's 2/3 full.

Lower the drop checker into the aquarium and trap a column of air within the glass piece.

Position the drop checker below the water surface within the aquarium and where CO2 bubbles from the diffuser are least likely to enter the device.

Leave the drop checker in the aquarium permanently.

Allow 6 hours for it to equilibrate with the aquarium water and then adjust CO2 dosing according to the colour (see details below).

Replace the solution every 4 weeks, or if the solution becomes cloudy.

If the colour remains blue you can slowly increase the CO2 dose.

If the colour of the solution turns yellow it indicates excessive CO2 in the water and dosing should be reduced.

Once the drop checker turns a light green colour you have the desired level of CO2 dosing.