Auto water change setup questions

[M4sonic]

I'm just about done remodeling my living room and started planning my new tank (woohoo!)

So i'm starting with my mixing station setup in my garage and i had rodi lines put under the flooring to allow me to do automatic water changes ( the missus is not so keen on me carrying buckets trough the living room)
It will be a pretty basic setup with 2 kamoer continuous duty dosing pumps, but i'm unsure on how to pull the water from the rodi and saltwater tanks.


Do i put a 1/4 inch connector in the bottom of the container and just plug in the line hooked up to my pump? ( i'm guessing this puts extra water pressure on the dosing pump )
Or do i put a connector in the top of the tank and have a line hanging inside the container?
Does it even matter?

Also, if i add the fresh saltwater to my sump this would be below the level of my container. any way to make sure i dont get a siphon if a pump fails?
For the wastewater i was thinking of pumping it into my old tank and using it as a quarantine tank and drilling that tank with an overflow that will go down the drain.

Any thoughts or problems with this setup that i'm not seeing?

Thanks in advance for the help!

 

[Jason_MrFrags]

place the lines so there isn't a chance for a siphon, perhaps into the overflow?
Where the pumps draw water from doesn't matter. connector through side or top works.