# calculating overflow size for tank size



## duzzy (Feb 9, 2008)

Hi there, 

how to I calculate the size overflow I need for my tank? Also from what i have read cyling the tank should be 5-6 times the volume, when calculating this for a tank with a sump do I include this in the size of my tank? so 130lt tank plus 80lt sump means i want my tank to cycle 5-6 x 200lt? 

Regards Darren


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## carpguy (Feb 3, 2006)

You could use the overflow calculator at Reefcentral.

For a 130 liter tank (about 35 us gallons) turning over 5 times an hour, I got a .55 inch (14mm) minimum diameter for the drain and a 3" (7.6 cm) minimum linear overflow.

I'd figure that the flow rate is what you want running through your display tank. I'd concentrate on what you'd want the flow rate to be there.


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## duzzy (Feb 9, 2008)

thanks carpguy, i found that calculator over the weekend....


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