Additives are perhaps the most confusing part of the saltwater hobby. When you walk into a fish specialty store there are often rows of pretty looking bottles that just scream “Buy Me!” So you take a closer look, but there seems to be a supplement for everything. Do I need to use additives, and if so, what additives should I be using?

No, you do not need to use additives and other supplements to have a successful reef aquarium. Then why do they sell additives? To help make your aquarium the best that it can be. With additives you do not always get measurable results, some will have positive effects and some can even have negative effects on your aquarium. When selecting an additive you generally get what you pay for! Low quality additives will have little or no positive effects on your aquarium. Additives will have many different names, do you best to figure out which category they fall under.

Calcium should be added by aquarists keeping a number of stony corals. Calcium is used by corals to grow. Calcium additives come in easy to use liquid bottles and more efficient dry mixes. Most Calcium additives contain Calcium Chloride and other agents to make the supplement more ionically balanced. For most hobbyists calcium levels can be maintained by routine water changes. Be sure to have a Calcium Test Kit.

Alkalinity should be added by aquarists keeping a number of stony and soft corals. Alkalinity is used by corals to grow. Alkalinity additives come in easy to use liquid bottles and more efficient dry mixes. Most Alkalinity additives contain Soda Ash or Sodium Bicarbonate and other agents to make the supplement more ionically balanced. Two-Part bottles of calcium and alkalinity are also commonly sold together and are designed to be ionically balanced. If you dose liquid calcium and alkalinity, add them at different times to prevent them from calcifying in the water. Most Alkalinity additives also act as a buffer, and like all buffers they will only temporarily raise pH. Be sure to have an Alkalinity Test Kit.

Stontium, Molybdenum and Iodine. These supplements are present in appropriate levels in most salt mixes and do not need to be dosed. Iodine should only be used by the advanced aquarist with the proper Test Kit because it is easily overdosed.

Trace Elements and Amino Acids. These products are often marketed to enhance coral growth and coral color. Be careful when purchasing these products, as you most certainly get what you pay for. These products do work for most advanced hobbyists with well established reefs, but the average hobbyist will see little or no visible results.

Phytoplankton and Other Coral Foods. For the average hobbyist, phytoplankton will increase coral polyp extension and greatly increase algae growth. Advanced hobbyists keeping carnations, sun polyps and gorgonians can use Phytoplankton to feed these corals. Another excellent coral food is Cyclops. You will see the immediate benefit of adding Cyclops into your aquarium as corals will extend their polyps to feed and fish will go absolutely crazy.

Fish Vitamins and Supplements are absolutely worthwhile. Look for supplements containing Omega Fatty Acids, Vitamin C, Garlic and Spirulina. These simple food additives will greatly boost your fish’s immune system and ability to fight disease. It will also enhance the color and vibrance of most fish.

As a final note, when purchasing an additive, read the label and determine if the product sounds too good to be true. There are many worthwhile additives and supplements available, but remember to purchase only high quality additives as they will have the greatest positive effect on your aquarium. Avoid additives with questionable packaging or that leak. If you were to purchase two additives, select a Fish Vitamin and Coral Food Supplement as it will have the greatest immediate effect on your aquarium.

Below are some general guidelines for water parameters. Please note these are only a general guidelines and not absolutes. Every aquarium is different and there are always exceptions to the rule.

Ammonia (NH3 – toxic): Zero (undetectable)

Nitrite (NO2 – non-toxic): Zero (undetectable)

Nitrate (NO3 – toxic): Zero (undetectable) is ideal, but less than 20ppm is generally acceptable.

pH: 8.0 to 8.4 is generally acceptable. pH will fluctuate based on CO2 levels in your home and aquarium. pH will always be lower in the morning and higher in the evening, so remember to test at the same time of the day.

Temperature: 74 to 82 degrees is generally acceptable with average aquarist aiming for 78 degrees. Once the temperature is in the appropriate range, the next step is to maintain a stable temperature with only minor fluctuations. A combination of Fans, Chillers and Heaters can be used to control aquarium temperature.

Salinity: Specific Gravity 1.020 to 1.026 is generally acceptable with the Fish Only aquarium leaning towards 1.020 and the reef aiming towards 1.025. Once the salinity is in the appropriate range, the next step is to maintain a stable salinity with only minor fluctuations. An auto-top device can be used to reduce salinity changes due to evaporation. Remember to use a calibrated Refractometer for accurate results.

Phosphate: Zero (undetectable) is ideal. An Aquarium with elevated phosphates is usually caused by overfeeding or using tap water rather than Reverse Osmosis water.

Calcium: 370 to 450ppm is generally acceptable. For most aquarists keeping soft corals and some LPS corals, weekly water changes is enough to maintain calcium. At 370ppm scientists believe that coral growth is maximized and any greater amount will have no effect on enhancing coral growth. It is more important to maintain a stable calcium level rather than an elevated calcium level.

Alkalinity: 2.5 to 4.3 meq/L or 7 to 12 dKH. (meq/L can be converted to dKH by multiplying meq/L by 2.8) The ocean has an alkalinity of approximately 7 dKH, but most home aquariums are maintained at elevated levels to help promote coraline algae. Some research shows that some SPS corals like Acropora may prefer an alkalinity closer to natural seawater, while soft corals may prefer a higher alkalinity near 12 dKH. While this research is debatable, most hobbyists can agree that it is important to maintain a stable alkalinity level.

Magnesium: 1350ppm is generally ideal. Sometimes aquarists find it difficult to maintain balanced levels of Calcium and Alkalinity and need to increase Magnesium.

Again, these are only general guidelines! Every aquarium is different and you may find great success and failure while maintaining these water parameters. In general, most salt mixes will mix to appropriate levels, but a few adjustments may be required. Remember to use high quality Test Kits. Using test kits from most general pet stores will provide you with inaccurate results.