Seachem Marine Buffer 500 gm

• Raises and maintains pH at 8.3 in all saltwater aquariums.
• Can be used safely in reef tanks.
• Contains borate for added stability.
• Contains magnesium to alleviate precipitation effects.

Marine Buffer will safely raise marine pH to 8.3. It will not raise pH above 8.3 even if inadvertently overdosed. Marine Buffer is a blended product and is not just sodium bicarbonate or sodium carbonate, commonly sold as a substitute. Such products can raise pH to dangerous levels if not used properly. Marine Buffer® contains sodium, magnesium, calcium, strontium, and potassium salts of carbonate, bicarbonate, chloride, sulfate, and borate.

Total Alkalinity is a measurement of three main ions: carbonate, bicarbonate, and borate. In saltwater, bicarbonate drives the pH toward 7.8, carbonate drives pH toward 9.1, and borate toward 9.5 or more. Because of the chemistry of buffering systems, the closer you get the pH to the pK of a buffering system, the harder it is for the pH to shift. So, if you blend a buffer so that the combined product drives the pH toward 8.3, then the more you use, the more stable the pH becomes. That is the principle behind Marine Buffer. It is a blended buffer that drives and holds your pH at 8.3 because of the blend. The catch to this seemingly simple solution is that most salt mixes contain substantial amounts of bicarbonate salts. This shifts the pK of the buffering system further towards 7.8, and a buffer that shoots for 8.3 will never quite get there. Thus, the pK of Marine Buffer is actually slightly higher than 8.3 in order to combat the influx of bicarbonate at every water change. Marine Buffer was the first buffer on the market which contained borate salts (which make a saltwater buffering system much more stable), and Marine Buffer remains the most effective pH buffer on the market for marine aquaria.

Compatibility

What it is. A dry pH buffer for marine and reef aquariums, dissolved in freshwater before dosing. Seachem builds it to bring pH up to and hold it at 8.3.

Dosage & Directions

Seachem’s own dose. 5 g (1 level teaspoon) per 80 L (20 US gallons), dissolved in at least one cup of freshwater before adding. Each dose raises alkalinity by about 1 meq/L.

Getting to 8.3. Dose daily until pH stabilises at 8.3. Seachem’s own guidance is this typically takes anywhere from one day to a week depending on where the tank starts. Once stable, cut back to biweekly or monthly dosing to hold it there.

Keep it apart from calcium. Don’t mix Marine Buffer directly with a calcium, magnesium or strontium supplement.

A troubleshooting note from Seachem. If dosing leaves a heavy precipitate that hasn’t cleared within 15 minutes, that points to poor ionic balance in the water and a water change is the fix, not more buffer. If the buffer isn’t holding pH at all, look at overstocking or overfeeding as the underlying cause before dosing harder.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 48 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.