Marine Buffer 250 g — Buffer pH 8.3 with Borates Seawater | Seachem

Seachem Marine Buffer is a multi-component powder buffer designed to raise and stabilize the pH at 8.3 in all saltwater aquariums. Unlike simple sodium bicarbonate or sodium carbonate sold as substitutes, Marine Buffer is a blend of sodium, magnesium, calcium, strontium, and potassium salts in the form of carbonates, bicarbonates, chlorides, sulfates, and borates. This patented blend prevents the pH from exceeding 8.3, even in the event of accidental overdosing.

Main advantages

• Stabilizes the pH at 8.3 — impossible to exceed this level even in case of overdose
• Contains borates for increased buffer system stability
• Contains magnesium to mitigate the effects of precipitation
• Multi-salt mixture (Na, Mg, Ca, Sr, K) — superior to simple sodium bicarbonate
• Safe for reef aquariums

Use in marine aquariums

Total alkalinity is a measure of three main ions: carbonate, bicarbonate, and borate. Bicarbonate raises the pH to around 7.8, carbonate to around 9.1, and borate to around 9.5 and above. Marine Buffer is formulated so that the combined mixture stabilizes the pH at 8.3. Most marine salts contain significant amounts of bicarbonates, which lower the pK of the buffer system to around 7.8. Marine Buffer has a pK slightly above 8.3 to compensate for this influence. Marine Buffer was the first buffer on the market to contain borate salts and remains the most effective pH buffer for marine aquariums.

Dosage

• 5 g (1 level teaspoon) per 80 L (20 US gallons). Each dose increases alkalinity by 1 meq/L.
• Dissolve in at least 250 ml (1 cup) of fresh water before adding to the tank.
• Add daily until the pH stabilizes at 8.3 — from 1 day to 1 week depending on the original pH and alkalinity.
• Then, use every 2 weeks to once a month to maintain a pH of 8.3.

Precipitation diagnosis

In ionically balanced seawater, the Marine Buffer produces little precipitation or turbidity. If a significant precipitate forms and does not dissolve within 15 minutes, the water is ionically unbalanced. Perform a water change before continuing use. A slight white, flaky precipitate is temporary (magnesium carbonate) and will redissolve within 30 minutes; this is often observed when magnesium levels are high.

Manufacturer's precautions

• Do not mix directly with a calcium, magnesium or strontium supplement.
• If regular dosing is not enough to maintain the pH, check overcrowding, overfeeding, or other management practices as a likely cause.
• Effectiveness improves with continued use

Available formats

• 50 g
• 250 g
• 500 g
• 1 kg
• 4 kg

Why choose the Marine Buffer from ReefSolution?

The Marine Buffer is ideal for marine fish tanks or reef systems where the pH drops below 8.3. For reef systems with a high organic load requiring a more aggressive buffer, consider the Seachem Reef Buffer (pK 8.6). Monitor your parameters with the Salifert KH/Alk Test Kit or the Hanna Checker Alkalinity.

Frequently Asked Questions

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

The Marine Buffer has a pK of 8.3 and is designed for all saltwater aquariums, including fish systems. The Reef Buffer has a pK of 8.6 and is specifically formulated to counteract the more intense production of organic acids in reef aquariums populated with corals and invertebrates.

Can the Marine Buffer raise the pH above 8.3?

No. The formulation of Marine Buffer prevents the pH from exceeding 8.3 even in the event of an accidental overdose, unlike simple bicarbonate or sodium carbonate which can raise the pH to dangerous levels.

Why does a white precipitate form after the titration?

A light, white, flaky precipitate is a temporary magnesium carbonate that redissolves within 30 minutes, often visible when magnesium levels are high. A significant precipitate persisting for more than 15 minutes indicates an ionic imbalance requiring a water change.