Seachem Reef Builder raises carbonate alkalinity (KH) 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 may be used together. Use Reef Builder to raise carbonate alkalinity without affecting ph. Use Reef Buffer to raise carbonate alkalinity and ph. Reef alkalinity should be maintained at 3–5 meq/L (8–14 dKH). Alkalinity should not be allowed to fall below 2 meq/L. Comes in 300g bottle.