where can i get metric check valves?

[Wayne]

Is the water siphoning from the return pump outlets? If so bring them closer to the water surface. Or is it just volume from the display and the sump water level is too high? If so another sump or some mods to your sump may be in order (preferably another guy).

[reefwars]

drill some holes just under your waterline in your return facing down once water lowers past that point....syphon break

[cathyg_99]

Originally Posted by reefwars

drill some holes just under your waterline in your return facing down once water lowers past that point....syphon break

i have its still not enough...