Seachem Reef Builder

7 reviews

Seachem Reef Builder is designed to raise carbonate alkalinity without immediately impacting on pH for the benefit of your corals, helping then build strong exoskeletons to form a beautiful reef structure in your tank.


  • Reef Builder 300g
    code: 366 In stock Only 3 left in stock
  • Reef Builder 600g
    code: 363 In stock Only 2 left in stock
  • Reef Builder 1.2kg
    code: 367 In stock Only 2 left in stock

Product Information

To keep corals healthy you need the right level of carbonates and calcium. Seachem Reef Builder is designed to safely raise carbonate alkalinity without affecting pH levels.

Reef Builder contains all of the necessary elements such as calcium, magnesium and strontium to replace that naturally lost. Ensuring that these levels are maintained will mean that corals have everything they need for optimum health and development.

It will not immediately impact on pH but with long term use there will be a tendency to stabilize at pH 8.3. If you want to raise the pH, then Seachem Reef Buffer will raise carbonate alkalinity and pH. Both Buffer and Builder can be used together for the best results.



  • Use half a level teaspoon per 150 L twice a week.
  • Dissolve in at least one cup of freshwater.
  • Check alkalinity every 2 weeks and adjust dose or frequency accordingly.


  • 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.
  • 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: t=0.05va (t=teaspoons to add to top off water, v=volume of tank in US gallons, a=amount to raise alkalinity in meq/L).
  • For example, if you want to raise your alkalinity by 1 meq/L in a 50 US gallon tank, then you would add 0.05x50x1=2.5 teaspoons into the top-off water.

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