"Curious about calcium" survey

[Rikko]

65 gallon mixed (90% LPS) reef.
Ca floats around 420 ppm - when it hits 400 I nudge it up to 450-460 over a few hours.
Alk sits around ... I think 9dkh? I'm drawing a blank. Anyways, I park it right in the middle of "normal" seawater.


My alk supplement is just Arm and Hammer baking soda. I don't consume too much so I'm not worried about pH drop as soem folks seem to be.

My ca supplement is a Calcium Hardness increaser from the pool supply store. It's a 77% calcium chloride, essentially the same as Dowflake or Turbocalcium.

I test with Salifert tests a couple times a week, maybe even less than that now that I've more or less mapped the system's consumption.