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What Should the Calcium Levels Be Like in a Reef Tank?

Best Calcium Levels for Reef Tanks San Diego, CA

Biochemistry is one of the various aspects involved in fish keeping, and it requires more attention from aquarists who keep saltwater tanks. Understanding the water chemistry of a reef aquarium can go a long way toward keeping a healthy ecosystem for tropical fish, algae plants, invertebrates, live rocks, and microorganisms. Saltwater tanks must be kept at certain ranges in terms of alkalinity and calcium levels. The knowledgeable staff at Aquatic Warehouse would like to share some considerations when it comes to maintaining the ideal calcium level in a reef tank.

Important Parameters in Reef Tanks

For aquarists who live near coral reefs, scooping up sea water for setting up a new tank is a great idea for various reasons. However, if you live in an area with cold green water it’s not that easy, as the water tends to have high phosphate that contributes to more algae. Prior to establishment of the nitrogen cycle, ocean water will appear to be murky until aeration and filtration go into effect. Once the water looks as if you were snorkeling a coral formation, the chemical elements you’ll have to monitor include:

  • Salinity
  • Ammonia
  • Nitrates
  • pH
  • Alkalinity
  • Phosphates
  • Calcium

The ranges of the above elements are perfect in ocean water from the reef. Mother Nature takes care of keeping things balanced, but in a reef tank this task will fall upon you.

Saltwater Alkalinity and Calcium

Calcium and alkalinity levels are crucial in reef tanks because they’re the building blocks of marine skeletal structures, and these include shells and corals. If you intend to have interesting species such as harlequin shrimp, they’ll depend on calcium deposits to keep their shells healthy. Calcium is directly related to alkalinity, which can be measured by the pH level. You should keep this level at around 8.

Ideal Calcium Levels

Reef tank enthusiasts go through a lot of test kits that reveal the health of the ecosystem and prompt the next steps to take. They’re of the reagent kind and are interpreted through color changes. The levels you’re looking for should be around 400 to 450 particles per million (ppm).

Calcium Supplements

The salt mixes and filtered water like reverse osmosis that are suitable for saltwater species may not be sufficient to produce all the calcium needed for a reef tank. Adding calcium doses is a solution that requires observation and testing. This is a lot of fun for hands-on aquarists, but others may prefer calcium reactors, which are devices that require the installation of CO2 tanks plus regulators to release calcium minerals from calcareous materials.

Calcium levels are just one of the many things you need to know how to properly maintain if you have a reef tank. No matter what type of aquarium you have, you’ll need several key supplies to ensure the ongoing health of the tank’s inhabitants. Whether you need an aquarium temperature controller, beneficial bacteria, LED lighting, a filtration system, or any other aquarium supply, you can find what you need at Aquatic Warehouse. If you have any questions, don’t hesitate to give us a call at 858-467-9297 to speak with one of our friendly aquarium experts.


Contact Information

  • Address: 5466 Complex Street Suite 204
    San Diego, CA 92123
  • Phone: (858) 467-9297
  • Email: sales@aquaticwarehouse.com
  • Working Days/Hours: Mon - Fri / 10:00 AM - 7:00 PM
    Saturday / 10:00 AM - 6:00 PM
    Sunday / 11:00 AM - 6:00 PM


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