Calcium & Magnesium Refill Reagents

Benchmark Calcium & Magnesium Reagent Kit

Overview

The Benchmark Calcium & Magnesium Reagent Kit is a refill set for the Benchmark Calcium & Magnesium Test Kit. It includes the liquid and powder reagents used to run both the calcium and total hardness procedures, so you can continue testing without replacing the full kit.

This reagent set is intended for reef hobbyists who already have the required testing tools and want a convenient way to restock their calcium and magnesium test supplies.

What It Does

This reagent kit supports calcium testing in ppm and magnesium calculation in ppm using the Benchmark calcium and total hardness methods.

Calcium (ppm) = mL calcium titrant used x 600

Magnesium (ppm) = (1701.35 x mL total hardness titrant) - (363.87 x mL calcium titrant)

It is useful for monitoring major-element consumption, checking dosing adjustments, and maintaining stable calcium and magnesium levels in reef aquariums.

Who It’s For

This reagent kit is intended for hobbyists who already own the Benchmark Calcium & Magnesium Test Kit hardware and need replacement reagents for continued testing.

How to Use

Calcium Test

1. Add 5.00 mL aquarium water to the test vial.
2. Add 1.00 mL of 4% sodium hydroxide.
3. Add one level scoop of calcium indicator powder.
4. Slowly add calcium titrant while swirling.
5. Stop when the color changes to purple.
6. Calculate calcium using: mL x 600

Total Hardness / Magnesium Test

1. Add 5.00 mL aquarium water to a clean vial.
2. Add 0.50 mL pH 10 hardness buffer.
3. Add calmagite indicator.
4. Slowly add total hardness titrant while swirling.
5. Stop when the solution turns pure blue with no red or purple tint remaining.
6. Use the calcium and total hardness readings together to calculate magnesium.

What’s Included

• 118 mL calcium titrant bottle
• 118 mL total hardness titrant bottle
• 118 mL 4% sodium hydroxide bottle
• 118 mL pH 10 hardness buffer bottle
• Calmagite indicator bottle
• Calcium indicator powder container

Important Notes

• Reagent refill only
• Designed for the Benchmark Calcium & Magnesium Test Kit method
• Uses a 5.00 mL sample volume
• For saltwater aquarium use
• Store reagents sealed at room temperature
• Protect indicator solutions from light and keep powder reagents dry
• Keep out of reach of children

Purchase Confidence

The Benchmark Calcium & Magnesium Reagent Kit gives you a practical way to keep testing without replacing the full kit. It is a straightforward refill option for reef hobbyists who want to stay consistent with calcium and magnesium monitoring.