Reef Buffer 250 g — Buffer pH 8.3 pK 8.6 Récifal | Seachem

Seachem Reef Buffer is a powdered buffer specifically designed for reef systems, formulated with a blend of carbonate and bicarbonate salts that produces a pK of 8.6 in seawater. This high pK helps achieve and stabilize a pH of 8.3 in reef aquariums, where the high organic load of reef inhabitants constantly pushes the pH down—a challenge that competing products based on simple sodium bicarbonate (pK 8.3) cannot overcome.

Main advantages

• pK of 8.6 in seawater — designed specifically for reef environments, not fish-only systems
• Stabilizes pH at 8.3 without risk of accidental overshoot.
• Simultaneously increases pH and carbonate alkalinity
• Optimized blend of carbonates and bicarbonates — superior to sodium bicarbonate alone

Use in reef aquariums

In a reef system, the multitude of organic acids produced by corals, fish, and invertebrates forces the pH down much more than in a marine fish-only aquarium. A buffer with a pK of 8.3 (like competing products) ends up maintaining the pH only between 8.0 and 8.2. The Reef Buffer's pK of 8.6 compensates for this acid pressure and allows for a stable pH of 8.3. The Reef Buffer also increases carbonate alkalinity. However, if pH is not a concern and only alkalinity needs adjusting, Seachem Reef Builder or Seachem Reef Carbonate are the recommended choices.

Dosage

• Check the pH and alkalinity before 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
• Adjustments are needed every 2 weeks to twice a week, depending on the system.
• 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, 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 pH regularly drops below 8.2, the Reef Buffer is the solution. Combine it with Seachem Reef Builder for independent alkalinity control and Seachem Reef Advantage Calcium for calcium. Monitor 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 is designed primarily to raise pH (with a secondary effect on alkalinity). The Reef Builder increases carbonate alkalinity without immediately affecting pH. Both can be used together.

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

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 reef systems and achieve a stable pH of 8.3.

Why isn't my pH rising despite the Reef Buffer dosage?

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 balance.