Using an ATO as a water change pump?

[Mindflux]

I apologize if this is a widely discussed subject. I didn't have luck finding anything on it.

I'm working on getting my first SW tank set up and researching ATOs. In the midst of doing so I couldn't help but wonder:

If I turn off the ATO before siphoning out my water for a water change, and then take the inlet side of the ATO hose and put it into my freshly mixed saltwater bucket and turn the ATO back on.. would this not (slowly) re-add new saltwater to my tank until the float switch is activated?

Then all I'd have to do is re-direct my inlet hose back to my RODI/Kalk water supply. Easy "more than one function" type scenario. If this is feasible (or not) how quickly do you add SW back to a tank on a water change? At first I'd be using buckets and having to find a way to diligently pour it into the tank until I get some other type pump to do the work. (maybe just an aqualifter)

Thanks for all your help and kindness.

[Teresa]

You should be able to google this - try "auto water change top off" or any combination thereof. I've recently done a ton of research for ATO for my very small tank and ran into a lot of discussions on this topic. Most people say they turn off the ATO, drain the water for the water change as normal, then hook up the ATO pump to the new saltwater and the pump will fill the tank to the correct level due to the float switch. It sounds like you'd like to do both simultaneously - as you drain the water the pump would bring in the new saltwater? I remember reading on another discussion forum someone that did water changes like this and it worked well.

[Mindflux]

I'll check google, but no I want to do just as you said others are doing (not a simultaneous drain/fill scenario)

Turn off ATO

siphon or pump water

move ATO inlet to fresh SW mix

turn on ATO

wait for ATO to finish filling back up

move ATO inlet back to RODI/Kalk solution.

[+Jakedoza]

I essentially do this already.. but my salt mix tank is in the garage with a mag5 and my tank is on the other side of the wall... hole in wall... hose through wall, and into sump.. For some this may be more complicated.