5
1. Theory
The pH value is an electric value that is a parameter for the acidity of water. In the aquarium, the
pH value together with the carbonate buffer system is of special interest.
- In a fresh water aquarium, the pH value is responsible for the percentage of free CO
2
that is
used by green plants for photosynthesis. Fertilization with CO
2
has been well-established for
fresh water aquaria as base for a good plant growth. With the pH controller, the pH value can
be adjusted to a given set point and kept constant by adding CO
2
automatically.
- In a saltwater aquarium, the pH value and CO
2
-addition are used in combination with a calcium
reactor. The addition of CO
2
into the calcium reactor is controlled by the pH-controller. In
addition, also Kalkwasser can be dispensed to increase the pH value after switching the control
range (No. 9).
2. Delivery
The Aqua Medic
pH controller
needs a separate pH electrode and corresponding calibration liquids
to start work. The regulating unit (solenoid valve, dosing pump) can be connected to the adaptor
plug.
Description of front panel:
1. Display
6. Set point adjustion
2. Display/relay on/off
7. Connection for electrode (BNC-plug)
3. Set/measuring switch
8. 220 V-plug / socket for regulating unit
4. Calibration knob, pH 7
9. Control range (turn left – pH decreases,
5. Calibration knob, pH 4
turn right – pH increases)
3. Starting and calibration
1. Connect to 100 – 240 V.
2. Connect the pH-electrode (No. 7).
3. Set switch (3) to „pH“ (measuring).
4. Insert the electrode into the buffering solution pH 7. After 3 minutes, turn knob 4 (CAL pH7)
until the display shows pH 7 (use a small screw driver).
5. Flush electrode with distilled water.
6. Insert electrode in buffer solution pH 4 (or pH 9, depending on the desired range). After 3
minutes, turn the knob (5) until the display shows pH 4 or 9.
7. Adjust control range (MODE No. 9). Left switch for pH decrease, right switch for pH increase.
During operation, the point (No. 2) will flash.
