Plumbing question ?

[kien]

what is the Eheim canister for?

As for the Herbie, it appears you have it set up properly in your drawing. The gate value allows you to adjust the flow of water from the Display Tank/Overflow box, into the sump. This effectively allows you to control the height of the water in the overflow box. Typically you want the water in your overflow box to be well above the main drain pipe so that you don't get that slurping and gurgle noise due to water and air getting sucked into the main drain pipe. The emergency pipe is left wide open in the event that something gets into your (slightly closed) main drain pipe and clogs it.

[belzebuth]

Since the skimmer is external.. I use it as a pump and sometime will run carbon in it if needs to

Sorry I should have specified.

[Cal_stir]

The return pump will need to be self priming

[belzebuth]

I guess I will have to look at the current pump... not sure if it's "self priming" humm...

[intarsiabox]

Originally Posted by belzebuth

I guess I will have to look at the current pump... not sure if it's "self priming" humm...

This was mentioned because in your drawing you have the return pump having to draw water up out of the sump. Because the plumbing to the suction side of the pump is vertical, the pipe will have no water in the line at start up and pumps can't pump air. An option would be to drill a hole for a bulkhead towards the bottom of the return section of your sump that the pump's suction line can be attached to and have the pump sitting at the same level as the bottom of the sump and not elevated. Option B would be to leave it as you have in drawing and see if you can find a PVC foot valve to attach to the intake pipe in the sump. This way you would only have to fill the return line with water once and the valve will prevent the water from pouring back out of the line when the pump is turned off, hence keeping your prime.