How to Convert Dextrose for Saltwater Fish

Sugar, or dextrose, is used in reef and other saltwater tanks to reduce the nitrate and phosphate levels. The dextrose, as a carbon source, encourages the growth of beneficial bacterial colonies that neutralize nitrates as well as phosphates. Proper oxygenation of the aquarium is necessary for this process to occur safely, and a skimmer must run to capture the resultant organic matter.

Things You'll Need

  • Table sugar (dextrose)
  • Protein skimmer
  • Nitrate and phosphate test kits
  • Filter carbon
Show More

Instructions

    • 1

      Check to see that nitrate and phosphate levels are in a reasonable range. Use nitrate and phosphate test kits. Do a water change to rectify the higher levels before dosing. Assure there is no illness or other disease in progress in the aquarium by checking for discolored corals, fish exhibiting lack of appetite, agitated or scratching activity, an excess slime coat, or white or golden spots as if they had been sprinkled with dust.

    • 2

      Attach and run the skimmer. Check to see that the skimmer is removing the organic matter by checking the receptacle for muddy foam. Run the skimmer constantly to ensure a high dissolved oxygen level during dosing. Add carbon to the tank's filter.

    • 3

      Add 1/4 teaspoon of sugar to 20 gallons of water. Add this amount of sugar to the tank every other day. Test the nitrate and phosphate levels every day until a stable reading occurs. Immediately reduce the dosage to half when the stable reading occurs or when the film of bacteria is noticed. Watch the fish for signs of distress such as shaking, darting or rapid gill movement. Do a water change immediately and stop dosing if the fish are stressed.