FAQ: I've heard Seachem Reef Calcium™ has sugar in it and will promote algae growth. Is that true?

A: No. This is a faulty assumption based on the premise that polygluconate is the same as glucose. Polygluconate is not a sugar any more than cellulose is a sugar (it's a polysaccharide). Cotton is almost pure cellulose, if you saw some cotton would you consider that to be a sweet treat? Polygluconate can be broken down into gluconate. The corals also can break it down and use it as a carbon source, as does your biological filter (some people even add ethanol to their system to "jump start" their biofilter... it's the same principal). In this vein, one side effect sometimes seen when using Reef Calcium™ is a dip in nitrates (if they were already up of course). The use of Reef Calcium™ presents no more of problem with respect to adding too much organics than does feeding your fish. Gluconate is a carbohydrate; fish foods also contain carbohydrates, either directly or within cellular DNA/RNA (DNA and RNA both contain cyclic carbohydrates (5 membered furanose rings) as their backbone). So the risk of a problem from Reef Calcium™ is equivalent to the risk from using fish food. The key here is that Reef Calcium™ is not being added in excess to what the tank can support. When the calcium is utilized the carbon component is also necessarily utilized and will not build up. If you overfeed your fish you're going to cause a problem, and if your overuse Reef Calcium™ you can run into a similar problem.