could someone explain how to setup an auto top off system

[rdefino]

I've been looking at the JBJ Automatic Top Off and I'm not sure how to set it up for my lay out. My main tank is on the 1st floor and all filter systems are below in the basement. I have access to the tank for the basement.

Now do I have to add the top off water to the main tank or the sump. I'm confused there.

Thanks for any help.

 

[kumdoalan]

I dont know.
I have never planned to use such a thing.
but I can tell you that I have seen a system where a guy had everything for his many tanks hidden in a filter room.
He had automatic top offs connected to his sumps so that there was nothing except the hidden water lines running to the fish tanks