Alkalinity is the single most important parameter for SPS color and growth. Drift over 0.2 dKH/day will brown out colonies. Here are the three proven dosing methods.

Two-part (BRS Pharma)

Most flexible. Dose alkalinity, calcium, and magnesium independently. Best for mixed reefs.

Kalkwasser

Cheapest. Saturated calcium hydroxide solution dripped via ATO. Raises pH as a bonus.

Calcium reactor

Set-and-forget. Best for SPS-dominant tanks consuming >1 dKH/day.

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