9.3 Setting the required level of CO
2
supply
The CO
2
supply rate (CO
2
bubbles/minute) required to achieve the desired pH depends on a
variety of factors, such as the types of plants in the aquarium, motion of the water, surface
area/volume ratio, etc. The appropriate CO
2
supply level thus requires to be determined indivi-
dually for the specific aquarium concerned.
• Recommendation: Begin at approx. 10 bubbles per minute per 100 l of aquarium water,
i.e. 2 x 10 = 20 bubbles per minute for a 200 l aquarium.
• After 1 day, check with the pH-Controller whether the desired pH value is achieved at this rate
and the device is able to perform its control functions in the correct manner, i.e. whether the
connected solenoid is switched off intermittently.
• If not, the number of bubbles should be increased to approx. 15 bubbles per minute per 100 l
of aquarium water. Check again after 1 day. If necessary, increase the number of bubbles
further in small steps until the desired pH is attained.
Please observe the instructions for use of the employed CO
2
fertilizer system
9.4 Table: Correlation between pH value,
CO
2
content and carbonate hardness
10 Special functions
10.1 Automatic pH setting
The “Auto” funtion enables the ideal CO2 content (approx. 20 mg/l) to be set directly, without
having to refer to the table:
• Press “Auto” key: The green LED flashes, the most recently set value appears on the display
(factory settings: 04). Enter the carbonate hardness measured in the aquarium with “+”
and “-”.
• When the keys remain unused for 3 sec., this value will be adopted. The pH-Controller
calculate the exact corresponding pH value automatically and sets the system accordingly. The
LED lights up in continuous mode.
• To check the set pH value: Press “pH” key: The set value appears on the display for 3 sec.
Example: Entered carbonate hardness 6 °d
The pH-Controller sets pH 7,0 automatically (= 20 mg/l CO2).
• To switch off the “Auto” funktion: Press “pH” key and then enter the new setting witch “+”
and “-” while the green LED is flashing.
Setting range: Carbonate hardness 1 - 20 °d.
30
