overflow boxes…
I just recently fitted an overflow box to my 55G, the problem is that it won’t allow me to fill my tank up, if i tuck the box right up under the inside lip of the aquarium, the system sucks all the available water out of the box then air gets in and stops the system working, if i lower the box in the aquarium all is fine but means i have to have my water level about 3" from the top of the aquarium, i am puzzled?
Terry.