Thanks Reggie. I checked the measurements. The 6" is 16" from the barbed fitting.
The 4" is 12" from barbed fitting.
Coming from my skimmer plug is 21" after sitting on it's stand. So yes. Either one will work.
I have o space under Cabinet. It will have to go on the side of the cabinet. My apartment already looks like a science lab.
If I can make sure the flow runs down hill properly, I will get the 6".
Thanks Adam. They look good as well. But the Octopus wc , They have the new feature on start up a delay so the main return pump can have time for the sump level to be correct before the skimmer pump turns on.