I’m looking to build a sump. How do I decide how big to make my overflow and how do. I decide how many gph for return pump. How do I figure out how much of each?
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ok thanksFigure out your turnover goal based on the display tank size, then assume an overflow can handle about 50 gallons per hour per linear inch - that’s the rule of thumb I always use.
Thanks!For return flow I base it on 3x to 6x the tank volume.
For the overflow size, I've always used the calculator on reef central.
Drain/Overflow Size
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I am pushing 3500gph through 24 inches of weir. Your rule of thumb seems excessively conservativeFigure out your turnover goal based on the display tank size, then assume an overflow can handle about 50 gallons per hour per linear inch - that’s the rule of thumb I always use.
Your rule of thumb seems excessively conservative
Also when building a sump be sure to calculate for drain back from not only your piping but what will back siphon from the tank.I’m looking to build a sump. How do I decide how big to make my overflow and how do. I decide how many gph for return pump. How do I figure out how much of each?
how do i do that?Also when building a sump be sure to calculate for drain back from not only your piping but what will back siphon from the tank.
how do i do that?
ok thanks for the helpPipe
Then you will need to look at your return pipe's exit depth in your tank. Until that pipe or pipes suck air it will siphon back water into the sump. Some people will drill a hole near the water line to prevent much water from siphoning back into the tankPipes with Water Content - Weight and Volume
Estimate water content in pipes - weight and volume.www.engineeringtoolbox.com
Ok thanks for the help!Figure out the low drain down point of the tank - that's probably the return nozzle, but it could be the bottom of the overflow teeth also. Based on internal tank dimensions multiply length x width x amount of drain down and then divide by 231 to give you gallons. For example, in my tank the internal length is 94 inches and the internal width is 34 inches. When my pump stops, I get slightly less than one inch of drain down. So, 94 x 34 x 1 / 231 = 13.8 gallons ….. round up to account for water volume in the return and drain pipes and it's 14 gallons.
What I do is more of a trial and error method.how do i do that?
OK Thanks!What I do is more of a trial and error method.
First I set the return nozzle in the tank as high as it will go without causing bubbles on the surface.
Then fill with water ( part of my freshwater testing ) and fill the sump with water about 2" above the return pump suction, then turn the pump on. If the pump starts sucking air add a little more water so that it's a 2" above the pump.
With the overflow full and running, mark the level in the sump ( tape or sharpie), then turn the pump off.
The inches of water that returns to the sump is the room in the sump you need to make sure is available all the time, and give yourself a couple inches to spare for safety measure.
Do this 2-3 times.
Ok thanks.Overflow should not be a design concern, try to put a bean animal overflow and it will handle all the flow you want from your return.
For return rate, I like slow return rate 2-5x tank volume, and take into consideration some systems require a desire return rate like Triton that suggest 10x.