8
Fig. 3: Holding unit EVO 501
By using the mounting profile (11), the retaining plate (7) can be fastened to a bar or vertical pane. Further
down, a second profile (12) can be mounted as a spacer. The distance can be adjusted by using the screws
(12a) so that the retaining plate hangs down vertically. On the opposite side of the mounting profile, the
connecting piece (9) for the adjustment screw and holding plate are mounted. To do so, the adjustment screw
(8) has to be put through the hole (9a) of the screw holder, then it has to be screwed in the thread (10) of the
holding unit. This can be moved up and down by turning the screw (8). The skimmer is hung up by putting the
laterally mounted holding bracket into the slot (10b) of the holding unit. In order that the skimmer hangs
straight, a second holding unit with rubber feet (no picture) will be fixed as a spacer at the bottom of the
retaining plate. The skimmer is adjusted in such a way that the discharge is above water level. Especially in
freshly set up aquaria, skimmers can rarely be regulated in such a way that constant foam production occurs.
This is only done when the aquarium is filled. To prevent overflowing of the foam cup uncontrollably, the skimmer
must not be immersed too deeply in the water (water level 1 - 2 cm below the discharge [Fig. 1, No. 7]).
Set-up in a filter chamber:
The EVO 501 can also be mounted at a glass pane of a filter chamber. The skimmer’s discharge (Fig. 1, No. 7)
is extended downwards to give a safe support. The skimmer needs about 20 - 23 cm immersion depth. First
immerse only 1 - 2 cm below the lower edge of the discharge (Fig. 1, No. 7).
5. Starting/Operation
The system can be started when it is correctly installed. After switching on the pump, air is automatically drawn
into the skimmer. To minimize the noise level, connect the air inlet tube with the blue connecting piece of the
silencer supplied. Fix the silencer with the holding unit on the aquarium or filter system above water level.
The needle wheel breaks the air into small bubbles. This method eliminates the greater proportion of noise.
After the initial start, it might take a few days until the foam production is ideal. This is due to a reaction between
the surface of acrylic glass and aquarium water. Equilibrium of electrical charges takes place. The quantity of
liquid and organic substances is dependent on the pollution of the aquarium.
In the discharge of the skimmer, there is a sponge that needs to be cleaned regularly.
6. Problems
Adjustment
The skimmer is adjusted by using the water level controller so that it works to its optimum.
The water level in
the skimmer has to be adapted for foam production. If the foam is too wet, the water level controller (Fig. 1,
No. 4) has to be further opened and thus the water level lowered. If the foam is too dry, the process has to be
done vice versa.
Air bubbles in the outflow
If the skimmer is added to an existing aquarium, there might be a high concentration of organic substances
already dissolved in the water. This results in very tiny bubbles in the skimmer. These tiny bubbles remove
organic substances effectively, however, it may happen that some of these bubbles are drawn back into the
