Sump Volume help

[Victor1046]

How much water should be in a 20 gal sump (110 gal)

half full????

Thanks for your help

 

[AZDesertRat]

Only you will know. It all depends on how much room you need to safely contain the amount of water that will backflow during a power outage. In my case I have a 30G sump and keep about 8 gallons of freeboard at all times but only really need about 4, the rest is a safety factor. You need to determine where you are going to place the returns and than calculate how much water is contained in however many inches of depth that amounts to.

 

[Victor1046]

thank you for your response...

freeboard being water in the sump?

Thanks

 

[TheSaladCo]

Depends!

Depends!

How does the water get below?
If it is from an overflow - make sure that in a power outage - the water level is low enough that your sump will not overflow.

 

[jer77]

The amount of water that drains into your sump during a power outage depend on a few things. Basically how far down the outlets and overflow teeth are into the water. Take which ever is deeper and measure how many inches it is deep. Then calculate how many gallons it is and this is how many gallons you should have empty in your sump. You should leave a little extra.

 

[AZDesertRat]

Freeboard is the free space above any normal high water level.

 

[Victor1046]

The water gets to the sump by a built in overflow in the tank
and holds approx 2 -3 gallons.

Thanks for all of your input..

Always learning....

 

[AZDesertRat]

With your internal overflow do you have a standpipe installed? This will reduce the amount of water that siphons back to just what is above the height of the standpipe so only maybe a few quarts will go down to the sump in a power outage. The other piece of the puzzle is the return placement(s). Keep them close to the surface and only an inch or so siphons back. If they are lower than that then it can overflow a much larger quantity. Some will recommend drilled holes in the returns or check valves but both are prone to failure. The best method is keeping the return outlets shallow so the entire overflow nozzle is exposed to air and breaks suction.