Fig. 2: DC Runner 800
1. Sealing plug
2. Filter basket
3. Pump motor
4. Rear bearing
5. Needle wheel
The pump DC Runner 800 is operated by an electronic safety transformer at AC 110 – 240 V / 50 – 60 Hz and
24 V DC output. Power consumption of the pump is max. 7 watts, protection rating is IP X8. To open the pump,
release the pump lock (Fig. 2, No. 8) by turning it. The pump must be mounted with the suction side
upwards (see Fig. 1), otherwise the pump may stop.
3. Theory
Protein skimming is a method of physical water treatment. It uses a phenomenon known from our daily
experience: the adhesion of surface active substances to air water layers. If we add a drop of oil to a water
surface, a thin film is produced with a thickness of only one molecule. Surface active compounds like proteins
behave in the same way. The skimmer EVO 501 uses its air bubbles to create a large water surface for the waste
substances to attach themselves to. These air bubbles are forced into the reactor-pipe in such a way that they
undergo a long contact time within the counter-current. Enriched with organic substances, they rise to the top
and form a firm foam that is dehydrated and pushed into the collection cup. This method removes organic
wastes from aquarium water before they become part of the biological waste treatment cycle.
The venturi pump draws water out of the aquarium or filter chamber, mixes it with air in the pump housing
which is then cut into small air bubbles by the needle wheel (Fig. 2, No. 5). This water/air mixture is then
pumped into the reaction pipe where organic substances are taken up by air bubbles. Foam is formed and
pushed into the foam cup. The purified water leaves the skimmer via outlet and is directed back to the aquarium
or filter sump by the discharge (Fig. 1, No. 7).
4. Set-up
The EVO 501 is a skimmer that can be set up in various ways:
1. As an internal skimmer, directly mounted on a glass bar or aquarium pane.
2. Hung on the overflow edge of a filter chamber.
Set-up as an internal skimmer in the aquarium:
First of all, the skimmer has to be put together according to Fig. 1. It can easily be mounted at the aquarium
pane or a glass support by using the holding unit. The best place for mounting is either at the side or back –
well accessible but protected. The pump is put into the connecting piece (6) of the skimmer, the cable points
downwards and the air hose upwards to connect to the silencer (14). The sound absorber can be attached to
the foam cup (2) or an aquarium pane by using the holding unit (15). To do so, take off the protective plastic
film from the tape. The adhesive surface must be clean and free of grease.
6. Front bearing
7. Housing's sealing
8. Pump lock
9. Seals for pressure connections
7