[bpimm]

Alex if you go with the Submarine UV Sterilizer the light is switched separately from the pump, so you can run the pump 24/7 and switch the light with a timer. I have one and like it.

I also has a lot bigger sponge for filtration than the other one linked above.

 

[bpimm]

I have not had a problem with water leakage in mine. you might try a little Vaseline on the O rings when you put it back together.