Calfo style overflow

[tperk9784]

Anyone use a Calfo overflow on their cube tank? If so how did you plumb it?

 

[jerryreefrigger]

I think the idea behind Calfo's overflows is using 2 reletively large diameter pipes so that they act as drains and not syphons. This works for noise elimination, but if one of the drains fills up with too much water, it will start a syphon and then girgle when air enters back in.

However, in order to facilitate more flow, one can force one of the drains to always be a syphon by restricting the flow and the end of the pipe with a ball valve. It seems counterintuitive, but a perfect syphon (100% full of water) is whisper quiet. The other pipe then acts as a normal drain, accepting a minimal amount of water.

So, lets say your return pump flows 1000gph. The syphon drain will flow the majority of it silently, and then other pipe will make up the rest. It's a delicate balance, but once you match the flow of the pump with the controlled syphon, dial it back just a bit so the water level stays just above the larger drain.

see pic. Hope this helps.

 

[Bri Guy]

Couldn't you use that double plummed method on a tank w/any overflow box, thats a neat Idea and I haven't seen it yet.

I love the less invasive look of the calif comapred to a regular bulky overflow section.

 

[jerryreefrigger]

Yes, you can by adding a syphon control (ball valve) and modifying the height of the intakes.