Dosing calcium and alkalinity together in one blended solution risks precipitation - the two react with each other when concentrated together, which is exactly why Fritz RPM splits its buffer system into separate parts. A third part covers magnesium, which supports the whole balance.
Why Split Calcium and Alkalinity
Calcium and carbonate alkalinity react with each other at high concentrations, which is why a proper two-part (or three-part) dosing system keeps them in separate bottles dosed at different times rather than combining them in one solution that would precipitate before it ever reached the tank.
The Three Parts
- Part 1 Alkalinity - a high-purity carbonate alkalinity solution dosed alongside Part 2 Calcium, without the precipitation risk of a combined formula.
- Part 2 Calcium - a high-purity liquid calcium solution dosed alongside Part 1 Alkalinity.
- Liquid Magnesium - a concentrated ionic magnesium solution balancing magnesium chloride and magnesium sulfate in the same chloride-to-sulfate ratio found in natural seawater.
How to Dose the System
- Dose Part 1 and Part 2 at different times (not mixed together) to avoid any localized precipitation in the dosing container.
- Test regularly and adjust dosing based on actual calcium and alkalinity readings rather than a fixed schedule alone.
- Keep magnesium in range, since low magnesium makes it harder to keep both calcium and alkalinity stable at reef-tank target levels.
The Fritz RPM Buffer System is available at Marine Concept Supply - order online or pick up at our shop in Wheeling, IL. Shop Part 1 Alkalinity, Part 2 Calcium, or Liquid Magnesium, and browse more aquarium care products.
