Do I need a valve on sump plumbing?????

[intarsiabox]

I think 1" drain on a 50g is adequate. Have a valve on the discharge side of your pump and use it to tune your flow. If you are getting lots of bubbles from the discharge pipe into your tank close the valve until they stop, likewise if the return section of your sump keeps fluctuating, as it should remain at a constant level (with evaporation as the exception of coarse). It's that easy!