Overflow Box

1. Place the Overflow Box on the rear or side of 
the aquarium. 

The aquarium’s water level should be above the inlet of the O/F Box.

2. Place the pre filter mesh into the first chamber. This will stop any inhabitants from entering the box. 

3. Turn the adjustment screws located at the 
side of the Overflow Box to secure box the wall of aquarium. 

4. Connect airline tubing and control valve to 
the out top hosetail of the box.  

5. Measure the distance from the Overflow Box 
to the sump. 
You can use Flexible or Hard piping must follow as straight as possible path from the Overflow Box to the sump. There 
can be a little slack but not too much or the box 
will not operate correctly. 

6. Place a hose clamp over the end of each 
piece of flexible hose if required 

7. Once every thing is in position tighten the 
hose clamps so it is a snug fit. DO NOT OVER 
TIGHTEN them as you may crack the plastic. 

Starting the Overflow Box
 
1. Ensure you aquarium is full of water and aquarium water level is above the inlet of the overflow box.

2. Fill the end priming chamber of the Overflow Box with water until the water begins to pour over the outlet chamber and down the piping to the sump. 

3. Now suck all the remaining air out of the centre "n" chamber till all air is rid and water starts to pour over the outlet chamber.

Check for leaks at this time. 

4. Water should stop flowing once it reaches the overflow boxes inlet lip.

5. Add power to the return pump (1200lph max on the Nano or 2000lph max on the larger twin outlet model) and the aquarium should start to fill and once the water is high enough and it will then begin to flow over the overflow box inlet.

6. The overflow box is now set up. Check over the next 24hrs for leaks within the loop and check aquarium/ sump water levels and adjust as required.

Over a period of time, air will begin to build up in the overflow box, you can either sump out manually or fit a powerhead fitted with a venturi to suck out the air automatically.