Seachem Reef Carbonate 250 ml

Seachem Reef Carbonate is a concentrated carbonate/bicarbonate blend that restores and maintains reef aquarium alkalinity.

Reef Carbonate is a concentrated (4,000 meq/L) optimized blend of carbonate and bicarbonate salts designed to restore and maintain alkalinity in the reef aquarium. Calcium and carbonates are essential to all coral growth. If either becomes deficient, coral growth will cease, followed by a rapid decline in coral health. To prevent this you must provide carbonates (Reef Carbonate) and calcium (Reef Advantage Calcium or Reef Complete). Used as directed, Reef Carbonate will not deplete calcium, magnesium, or strontium which usually tend to precipitate with increasing alkalinity. Reef alkalinity should be maintained at 3-5 meq/L (8-14 dKH). Alkalinity should not be allowed to fall below 2 meq/L.

Whereas competing products simply use sodium bicarbonate, Reef Carbonate is made with a blend of carbonate and bicarbonate salts. This blend of salts results in Reef Carbonate yielding a pK of roughly 9.0 in saltwater (higher than competing products). In a closed reef system, the multitude of organics produced by reef inhabitants tends to force pH downward, but the advantage of Reef Carbonates higher pK is a stabilization of pH around 8.3-8.4. Competing products formulations make them incapable of such a claim, so pH will always fall below desirable levels for a reef aquarium.

BEGINNER: Use 1 capful (5 mL) per 80 L (20 gallons) twice a week. Best if diluted into a cup of freshwater, then added. Check alkalinity every 2 weeks and adjust dose or frequency accordingly. ADVANCED: Check alkalinity, then follow dosing regimen above until alkalinity is adjusted to 4-5 meq/L. Each dose will raise alkalinity by about 0.25 meq/L. Size or frequency of dose can be adjusted, but do not exceed 1 meq/L per day. Thereafter, use as required to maintain alkalinity. EXPERT: After determining the alkalinity consumption rate, set up a continuous drip system. Use the following formula to determine how much to add to your top-off water: m=va (m=mL of product to add to top off water, v=volume of tank in gallons, a=amount to raise alkalinity in meq/L). For example, if you want to raise alkalinity by 1 meq/L in a 50 gallon tank, then you would add 50x1=50 mL into the top-off water. HINTS: Best to pour in gradually near strong water movement. Do not add to a sump or other area of slow water exchange. Use MultiTest: Marine pH & Alkalinity to measure total alkalinity or Reef Status: Magnesium, Carbonate & Borate to measure carbonate alkalinity. DO NOT OVERDOSE: Excess alkalinity may enhance the loss of calcium, magnesium, and strontium. Do not directly mix with any calcium, magnesium, or strontium supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

Part of maintaining stable reef chemistry — see our guide to KH (Alkalinity) for why this parameter is tracked closely alongside calcium and magnesium.

Part of maintaining stable reef chemistry — see our guide to Calcium & Magnesium for how this product fits into dosing a reef tank.

Compatibility

Marine and reef. It can be dosed with canister filters and skimmers running; add it to a high-flow area rather than to a sump or any still corner.

Do not mix it directly with a calcium, magnesium or strontium supplement. Dose them on alternate days or at least 30 minutes apart, and do not raise alkalinity by more than 1 meq/L in a day. Beginner dose: 5 mL per 80 L twice a week; target 3–6 meq/L (8–17 dKH).

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 72 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.