Check valve for low gph pump?

[vss]

I'm currently using a submersible pump with pretty low flowrate (300 gph, 6 ft head) for water change. I was trying to get a check valve to prevent the fish tank water from flowing back to the storage tank. I got one from a local hardware store today but it did not work since the pressure from the pump is not high enough to push the diaphragm open. Just wondering what you are using and if there is any particular one to recommend? Thanks.

Xiaofei :)

[ZX10R]

You might have gotten a check valve that has a spring in it they typically need more pressure to open. You need a swing check valve they need a lot less pressure to open. Here is what I am using look at the high flow pvc valve

http://www.mcmaster.com/#standard-check-valves/=lqbzzl

[vss]

Thanks ZX10R for the suggestion! Just ordered one swing check valve online.

Xiaofei :)

[ZX10R]

The smaller spring loaded check valves like in the pvc ones normally take 2-3 psi to open them. The high flow swing check valves take about .5 psi to open.