What Volume Sump?

[always4lora]

Hi'

What volume Sump would i need for a 280usg tank? Would a 30g sump do the job with a 5500lph return pump? Also is there a guide to how big of a whole i'll need for the overflow on the sump?

I've been informed that it's normally 25% of the volume of the tank meaning i'd need a 60g sump , can anyone confirm this?

 

[OldMan47]

Sumps are usually in the 20 to 30% of volume range for the simple reason that they need to hold enough water all the time to work effectively and they need to absorb the level drop in the main tank without spilling any water if the power fails and the pump stops. That means that they run only partly full most of the time and the size of the overflow determines how much they need to absorb when the pump stops pumping. The overflow size needs to be based on the size of your return pump. If you move x amount per hour into the tank, the overflow needs to flow at least that same amount to keep levels in both places constant. The specific sizes involved may be more readily found by asking on the saltwater part of the forum where lots of salty people end up keeping sumps for their tanks.