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Seachem Reef Builder


A blend of carbonate sources, Reef Builder raises carbonate alkalinity without immediately impacting on pH. Will not deplete calcium, magnesium, or strontium.

Carbonates and calcium are essential to all coral growth. If either becomes deficient, coral growth will cease, followed by a rapid decline in coral health.

Reef Builder ™ raises carbonate alkalinity without immediately impacting on pH. With long term use there will be a tendency to stabilize at pH 8.3. Used as directed, Reef Builder™ will not deplete calcium, magnesium, or strontium which usually tend to precipitate with increasing alkalinity.

Reef Builder™ and Reef Buffer™(below) may be used together. Use Reef Builder™ to raise carbonate alkalinity without affecting pH. Use Reef Builder to raise carbonate alkalinity AND pH.

Why Reef Builder?

Unlike the competition, Reef Builder™ contains calcium, magnesium, and strontium to compensate for the inevitable loss which occurs when raising alkalinity. It also contains sufficient magnesium to restore magnesium routinely depleted.

Seachem Reef Builder Directions

  • Beginner Use half a level teaspoon per 150 L (40 gallons) twice a week. Dissolve in at least one cup of freshwater. 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: t=0.05va (t=teaspoons 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 your alkalinity by 1 meq/L in a 50 gallon tank, then you would add 0.05x50x1=2.5 teaspoons into the top-off water.

500 g treats 32,000 L (8,000 gallons)

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$6.05 ea
SeaChem Reef Builder, 250 Gm (8.8 oz)
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$10.29 ea
SeaChem Reef Builder, 500 gm
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$18.81 ea
SeaChem Reef Builder, 1 Kg