Curious about others experience with this. I am currently manually dosing 2 part and considering either a doser or Kalk in ATO. Any feedback on thoughts of this approach or experience would be appreciated.
IMHO, it is a good approach and your corals will love you for it, but be mindful that your ATOs pump lifespan will greatly be reduced and not to mention all cloudy/milky residue in, and around it. Due to this, I personally have a separate dosing channel performing this duty.
I like to dose kalk precisely to keep levels stable. In an ato your daily evaporation changes, so you kalk dosage would change. I prefer an ecotech versa and an avast kalk stirrer to dose the same amount daily.
If you can, I'd lean towards dosing two part. If not, it'll still work. Like mentioned just make sure to clean your ATO pump frequently and expect a little cloudiness when it's first going into the tank.