Need a creative ATO solution

[Lemoncello]

In April I will be starting a new tank build of a Red Sea Reefer 750XXL. The design of the auto top off system is something that I haven’t nailed down yet. I would like to use Kalkwasser on the tank. With a tank this size I am not sure how much water it will evaporate daily which then will dictate the amount of Kalkwasser addition. I don’t have a basement or closet strategically located so I can’t make a big batch of Kalkwasser. The quantity would have to be the amount that can fit in the compartment under the tank (probably at most 5-10 gallons or a Kalkwasser Reactor). There is a sink next to this family room (the tank will be located in the family room) and I can put my RO/DI unit there and run a water line through the wall. Therefore, I will have on demand RO/DI water at the tank. I may just plumb a valve for me to refill the Kalkwasser container manually or it could be something more automated. I have also thought about metering in Kalkwasser and have the automatic top off fill RO/DI separately to maintain tank levels. Love to hear from people on a good set-up that minimizes the work and ensures a constant top off when I travel.

 

[clover128]

I'm planning to go with a neptune apex controlling as much as possible. They have a sweet ato solution, pricey yes, but I think it's worth it:

 

[Chris A.]

I’d look at how much water you evaporate a day and use a dosing pump to pump a little less than that at max if you need that much addition and use s ato to top off the rest. That way the alk/calcium will be added evenly every day and your ato will keep your salinity from swinging as well