The tube in the overflow box of my aquarium won't stay down, when I force it in the tank overflows ?
What type of filter do you have? I'm not sure what you are describing.
How to - Aquarium overflow / sump / refugium. Some tips
My 55gallon SW tank with 10gallon sump/refugium tank. This movie is to show the equipment and how it works.
overflow boxes... - Saltwater Aquariums - Reef Tanks Online Discussion
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? let me try again to make sense, i have the overflow outside box fitted, i also have the inside box fitted but when i put the inside box right up under the inside lip, it runs for about 1-2 secs then the 'U' tube fills with air and the syphon breaks, if i put the box about 3" from the top resting on some rockwork, everything is fine but obviously my water level is also 3" from the top.
