Hole location for closed loop

[NaCl_H2O]

you can't put them behide the calfo. then it's not a close loop.

Dan, why couldn't you put the inlet for the closed loop behind the Calfo <_< I guess if the sump pump stopped, the closed loop inlet could go dry, but is there any other reason? Sometimes I wish I had gone this route with mine :unsure

[dow]

I think that Dan's concern is that if you put it in the overflow box, that it might pull air through the lines, thereby making your tank int a saltwater jacuzzi.

[dan]

not only that but your closed loop pump might might pull more water than the water going into the calfo. now you have a pump that try to push all the water into the tank and nothing going to the filter. got a mop??? :o

[GaryP]

Just remember when you are building this that the idea behind a calfo is to have very little disturbance of the water surface with your returns. The theory behind a calfo is let the oily waste products accumulate at the surface and be removed by the overflow. Any turbulence at the surface would be counter productive for a Calfo. You basically want a concentrated waste product going to the sump.