Pump GPH

[Ksnell]

My pump in my sump just died on me, and I'm wondering if the one I had was either too cheap, or wasn't powerful enough for the job I had it doing. I'm using an external overflowbox with a 1" drain into my sump. My tank it 20 gallons, and the return line is approx. 5'. By my calculations I need a pump that's about 200gph...is that correct? I'm thinking about getting a pump that's rated at 296 just in case, but having one overrated for my tank shouldn't be a problem if I regulate the line with T-valves right? TIA.

 

[BillyZ]

The size of the pump you need should be determined by what your overflow is rated for and how high your pump has to push the water. IMO you should have a return pump that will push a maximum of about 80% of what your overflow can handle. This allows you to let the pump run at 100% as well as allow for some flow restriction in your overflow. Wether that restriction is from algae, a snail getting in the way, what have you. Restricting the flow on the pump adds back preasure on the pumps impellars. IMO, that back preasure only shortens the life of your pump.

JMO

 

[dskidmore]

That 5' measurement is your head rating. Diffrent types of pumps operate better or worse under a large head load. Look on the side of the box, the package insert, or the manufacturer's website for a "power curve" that will show you how much the pump is slowed by that 5' head.

200 GPH is your target flow for a soft coral reef, but you need a pump that pushes 200 GPH after moving the water up 5', not at 0' of head. All those ratings on the box are measured at 0' head.

 

[ellisz]

In applications I have used, a 1" drain will max out at a Mag7 but my head height was not 5 ft. If your not wanting max flow just get a mag 5. It is a great durable pump.