calfo?

[sharkboy]

What exactly is this calfo I have been reading about? I'm assuming it has something to do with water flow.

[GaryP]

A calfo is a type of overflow. Rather then a vertical overflow like you are probably more familiar with, its a horizontal tray that runs along the top of the back of the tank. It usually doesn't have teeth cut into it like a regular overflow.

The idea behind it is that its takes a smaller volume of water, from a shallower depth of water from the entire surface of the tank. Organic waste is lighter then water and accumulates at the surface of the water. By taking water just from the surface, you are getting the highest concentration of waste, in the smallest volume of water going to the filtration equipment in the sump. By reducing the volume of water going to the sump, you are increasing the residence time in the sump where the filtration equipment can work on removing the waste. Obviously, you don't want a monster return pump for this type of set-up. You also don't want a lot of flow across the surface of the tank. You want to allow the organic film to be undisturbed and not agitated so it can be skimmed off by the Calfo.

Since you are not getting a lot of flow from the return pump, you will need to add a lot more flow in the mid and lower levels of the tank with powerheads or a closed loop.

Did that explain it to you?

[demodiki]

Awesome explanation, Gary. Is this type of overflow built into the tank or is it added separately?