should be hooked up seperately. If you restrain the pump with the ball valve, you run the risk of running the pump hot because of the resistance.. As I states before, with an 18 watt UV
, you should be pumping no more than 200 gph IME
. Any faster, and it is not killing anything but, rather just being another return pipe.
problem could be due to oxygen exchange at the surface... the GPH
in the system doesn't mean much if the surface tension is 0. You need to have the PH
's creating turbulance at the surface...
Also, what kind of tank is this? FO
If it is a reef, what are you using for Alkalinity and Calcium supplement? If you aren't using anything to supplement even a FO
tank, how often do you do water changes? The salt will create at least a ph
of 8.2 when you mix it...