Man what a beautiful build, just read it from beginning to end! Will definitely be following this as it progresses. A couple questions:
Are you running a continuous duty dosing pump on your Calcium reactor setup to control outflow? I'm getting ready to pull the trigger on a similar setup and that failsafe seems to be a point of contention.
Also wondering where you got the flexi-hose for your mixing station I'm running braided vinyl connected to a male nipple on mine right now, but having the shutoff valve attached to the hard plumbing instead of at the end of the line is challenging to get to sometimes, and the braided vinyl tends to kink over time.
Thanks for the fantastic build thread!