I would get an X3 1st. I think this is the ultimate setup for running kalk:
Hydros control X3 starter pack ($322): includes X3, temp sensor, pH probe, wifi 4 plug outlet
Hydros water level sensor ($42)
Versa VX-1 dosing pump x 2 ($400) or perhaps cheaper pump if possible. Maybe
hydros single head pump.
Avast marine kalk stirrer ($300) or $200 with do-it-yourself kit.
Total: $1K or less if able to get cheaper dosing pumps.
Why do I think this is an ultimate setup?
Temp: you plug your heaters into the wifi plug and the
hydros temp sensor can prevent temp issues
Kalk: plug the versa (or other) dosing pump into the wifi plug and the
hydros can control the RO being pumped into your avast marine kalk stirrer and shut it off if pH is too high.
ATO: you can use the
hydros to run an ATO for your ATO. That is what I do. I use the
hydros water level sensor in my ATO container. Then run a long RO tubing from a large RO reservoir in the garage (or wherever) to a versa pump plugged into the
hydros wifi plug (or in my case I got a single wifi plug and used it in the garage). Then the RO tubing runs from the versa into my ATO container using a float valve for extra security. The
hydros turns the versa on when the sensor is dry but you can set it to run longer than necessary thus limiting the frequency of running the versa pump. This allows you to have a huge ugly RO reservoir hidden somewhere and your nice sleek ATO reservoir next to the tank.
Now you have temperature backup and reassurance. Kalk runs automatically with pH backup. Rarely need to fill the large ATO reservoir depending on its size (I will fill it once a month or so).
And you still have a sense port on the
hydros free for your actual ATO, or leak detector, etc. You also have an open plug on the wifi 4 plug strip for anything else you want to control (like the actual tank ATO pump, or your return which will shut off if there is a leak detected, etc).
For about $1,000 this seems like a great way to control a tank and run kalk for a decent price.
