Do I need one or two valves

Scratching my head on what you mean. Just put a ball valve between the pump and tank

What Brich said. Should be pump -> ball valve -> t union. That's how I've got it set-up on my 144 for the returns.

Most pumps are fine to restrict the outflow. Most will also use less energy. You can keep your pump wide open and route some water to run through the sump again but that sounds overcomplicated. Just dont restrict the intake on the pump and you will be fine

Put one on the line going to the sump. That way you can close it if you want all the water going to the tank.


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I assume that simply purchasing a new pump is out of the question? I only mention it because I've recently started researching DC pumps for my 240 gallon project, and they are amazing for several reasons: less energy used; less heat put off; and completely controllable flow rates. You can ramp the flow up or down as required with a digital controller attached to the pump. The salt water guys apparently turn them down or off when feeding - there's even a button for that which pauses or significantly reduces the flow for 10 minutes before going back to the set power level.

If that's not an option, then yes, a ball valve and a t union would work for you. I have had a ball valve on my Laguna 2000 pump since the day I set it up, and I've had no problems. I only have the flow restricted slightly, but if I let it go full blast, I'm pretty sure it will pump faster than my drains can accommodate. Have you considered using the t valve to have 2 returns into the tank? Maybe one on each side, or even on positioned lower in the water column?