Seachem Reef Carbonate 100ml


Seachem Reef Carbonate Raises carbonate alkalinity (KH) and is concentrated at (4,000 meq/L) it is also made with a blend of carbonate and bicarbonate salts.


Reef Carbonate Liquid

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).

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 Carbonate’s higher pK is a stabilization of pH around 8.3-8.4.

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.



  • 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 amount or frequency accordingly.


  • Check alkalinity, then follow addition regimen above until alkalinity is adjusted to 4–5 meq/L.
  • Each mL contains a minimum of 4 meq of alkalinity. Each 5 mL/80 L will raise alkalinity by about 0.25 meq/L.
  • Amount or frequency can be adjusted, but do not exceed 20 mL/80 L per day.
  • Thereafter, use as required to maintain alkalinity.


  • 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/4 (m=mL of product to add to top off water, v=volume of tank in litres, a=amount to raise alkalinity in meq/L).
  • For example, if you want to raise alkalinity by 1 meq/L in a 200 litre tank, then you would add (200x1)/4=50 mL into the top–off water. [For reference: 1 gallon=3.8 L].

  • NOTES:

  • 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.


  • 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 and carbonate additives are added on alternate days or at least 30 minutes apart.