20
=8
The auto-pH curve shows the levels for sets
u
403,
m
603 and
m
1003 which the pH computer
automatically maintains when the “auto pH“ option is activated. We recommend that this option
is activated for the safety of your fish.
13.2
The correct amount of CO
2
and the correct pH value
JBL recommends a CO
2
content of between 15 and 30 mg/l in aquarium water. This range is
marked with “CO
2
correct “ in the table above. 20 – 25 mg/l have proved to be ideal. This level is
not harmful to fish whilst at the same time promoting luxuriant plant growth.
•
Measure the CH of your aquarium water with the enclosed JBL CH Test Set.
•
In the section “CO
2
correct“ look for the pH value which is correct for the CH and the
desired CO
2
-value.
•
Gradually adjust the CO
2
bubble count so that this pH level is attained.
Please ensure that only those pH values are set which do not harm fish. This is the section of
the table labelled “CO
2
correct“.
13.3 Setting the CO
2
quantity
The amount of CO
2
which has to be added for the desired pH value depends on various factors
such as water movement, consumption by plants etc. and has to be calculated individually for
each particular aquarium.
•
Begin with about 15 bubbles per minute in the JBL CO
2
vario Reactor per 100 l aquarium
water (this corresponds to about 10 bubbles per minute using a bubble counter).
•
After one day check whether the optimum pH value set has been attained in the aquarium.
•
Should this not be the case, increase the CO
2
supply to about 20 – 25 bubbles in the JBL
CO
2
vario Reactor (about 14 - 16 bubbles in a bubble counter). If necessary, increase the
supply in further small stages until the required pH level is reached.
•
Check that the pH level is maintained, giving the right CO
2
level on the CO
2
permanent test
•
In the case of the
u
403,
m
603 and
m
1003 sets the pH computer automatically maintains
the pH level required.
14 Note on the pressure indicated on the pressure regulator
The CO
2
gas in the CO
2
storage cylinders is under high pressure. This pressure depends on the
ambient temperature. At room temperature (approx. 20°C) the left-hand pressure gauge shows
a pressure of about 50 bar. This increases if the room temperature rises. At 30 °C the gauge
therefore indicates about 70 bar. The pressure in the cylinder does not indicate the amount of
gas it contains. It remains constant in line with the surrounding temperature until shortly before
the cylinder is empty. The amount of CO
2
in a cylinder can only be estimated by weighing. The
empty weight (tare) of the cylinder is stamped on the cylinder. The total weight minus the tare
weight gives the amount of CO
2
.
The pressure in the storage cylinder is adjusted downwards by the pressure regulator to
an easily manageable pressure, known as the “operating pressure “. The right-hand gauge
indicates the operating pressure. In the JBL
u
001 and
m
001 pressure regulator fittings it is
pre-set at about 1.5 bar. This is the optimum pressure for the CO
2
fertilization of aquariums. If
required, however, the operating pressure can be adjusted using the setting screw. When the
operating pressure is adjusted it is important that CO
2
is released i.e. the adjustment screw
should not be closed as this would prevent adjustment of the pressure.
15 Changing cylinders
If the cylinder pressure (left-hand gauge) falls below 30 bar, the cylinder will need to be refilled
(refillable cylinders) or changed (disposable cylinders) in the next 2 – 3 days.
Disposable storage cylinders:
Disconnect the CO
2
hose from the pressure regulator and briskly unscrew the pressure regulator
anti-clockwise from the cylinder fitting. This creates an initial hissing noise. Unscrew briskly until
