Reef Buffer 500 g — Buffer pH 8.3 pK 8.6 Récifal | Seachem

Seachem Reef Buffer in a 500g format is a powdered buffer specifically designed for reef systems. Based on a blend of carbonates and bicarbonates, it produces a pK of 8.6 in seawater. This high pK helps stabilize the pH at 8.3 despite the constant acid pressure exerted by the organic load of reef inhabitants. The 500g format is suitable for medium-sized reef aquariums requiring regular pH adjustments.

Main advantages

• pK of 8.6 in seawater — formulated for reef environments, not fish-only systems
• Stabilizes pH at 8.3 without risk of accidental overshoot.
• Simultaneously increases pH and carbonate alkalinity
• Economical 500g format for regular reef pH adjustment

Use in reef aquariums

The corals, fish, and invertebrates in a reef aquarium produce a multitude of organic acids that force the pH down. Competing products based on simple sodium bicarbonate have a pK of 8.3, too low to compensate for this pressure—they only maintain the pH between 8.0 and 8.2. The pK of Reef Buffer, at 8.6, overcomes this limitation and stabilizes the pH at 8.3. Reef Buffer also increases alkalinity. However, if only alkalinity needs to be corrected without adjusting the pH, Seachem recommends Seachem Reef Builder or Seachem Reef Carbonate.

Dosage

• Check the pH and alkalinity before each use
• 5 g (1 level teaspoon) per 150 L (40 US gallons) increases the pH by 0.1 unit and the alkalinity by 0.5 meq/L
• Dissolve in at least 250 ml (1 cup) of fresh water, then add to the container
• Frequency: every 2 weeks to twice a week depending on system demand
• The alkalinity must not exceed 6 meq/L

Ionic balance diagnosis

If the alkalinity reaches 6 meq/L without the pH reaching 8.20, or if turbidity persists for more than 15 minutes after titration, the system is ionically unbalanced. To restore balance: perform a water change or adjust the magnesium and calcium levels to achieve a Mg:Ca ratio of approximately 3:1.

Manufacturer's precautions

• Do not exceed the recommended dose without checking the pH and alkalinity.
• Excess alkalinity can accelerate the loss of calcium, magnesium, and strontium.
• Do not mix directly with a calcium, magnesium, or strontium supplement — alternate days or wait at least 30 minutes.

Available formats

• 50 g
• 250 g
• 500 g
• 1 kg
• 4 kg

Why choose the Reef Buffer from ReefSolution?

If your reef tank's pH consistently drops below 8.2 despite water changes, the Reef Buffer is the ideal solution. Use it in conjunction with Seachem Reef Builder for independent alkalinity control and Seachem Reef Advantage Calcium for calcium. Verify your parameters with the Salifert KH/Alk Test Kit or the Hanna Checker Alkalinity.

Frequently Asked Questions

What is the difference between the Reef Buffer and the Reef Builder?

The Reef Buffer primarily increases pH due to its pK of 8.6, with a secondary effect on alkalinity. The Reef Builder increases carbonate alkalinity without immediately affecting pH. Both products can be used together for independent control of each parameter.

Why is the Reef Buffer preferable to the Marine Buffer for a reef tank?

The Marine Buffer has a pK of 8.3 and is designed for marine fish systems only. The Reef Buffer has a pK of 8.6, necessary to compensate for the higher organic load of a reef aquarium populated with corals and invertebrates.

My pH remains low despite the Reef Buffer dosage — what should I do?

If the alkalinity reaches 6 meq/L without the pH reaching 8.20, the system is ionically unbalanced. Perform a water change or adjust the magnesium:calcium ratio to approximately 3:1 to restore ionic balance.