Need help swapping-out sumps

[JurisHP]

Dear All: I am upgrading my sump and have some concerns. When I unhook everything, especially the hoses that attach to the bottom of the tank, how do I stop the water from draining out of the tank through the hoses? Do I have to empty my tank first? Or do I just close the valves and turn off the return pump?

 

[W1ngz]

Just lower the tank water level a bit so it's below the overflow and the return. Drain the hoses, AND close the valves to catch any slow running water.

 

[DnA-Aquatics LLC]

I would turn off your return pump. And then to be safe you should empty a few gallons out of your tank to make sure no water can get into your overflow. There are a few videos on youtube that go into detail into replaceing sumps. But as long as your flow is off and the water in your tank is lower then your overflow, no water should be flowing through the pipes into your sump.