Aquarium Fish

Curing and Acclimating Live Rock and Live Sand

posted: 05/15/12

Live rock needs to be "cured" to allow the plant and marine life, especially sponges, which live on the rock, to undergo a natural die-back, without polluting the aquarium water. As the organisms on the rock die, they produce a large amount of waste material that creates a very large ammonia spike that can be toxic to an existing system. This die-back occurs in all transported live rock and is necessary to provide a solid foundation for the remaining species to grow and flourish. Most of the very beneficial nitrifying bacteria survive the curing process by hiding deep in the pores and crevices of the live rock. In addition, some of the corals and invertebrates will not completely die off, and will begin to re-emerge in the new aquarium over time.

Both pre-cured and and live rock that is not pre-cured are generally available for the reef aquarist. Pre-cured live rock is harvested, sprayed with seawater, and scrubbed to remove unwanted debris. This spraying tends to drive out most unwanted species, including bristle worms and mantis shrimp. Rock that is not pre-cured contains a wider variety of organisms. Either pre-cured rock or rock that is not pre-cured can work well in a home reef aquarium and which one you choose is a matter of personal preference. Both types need to go through the same curing process before placement in a aquarium. The curing process for rock that has not been pre-cured generally takes longer.

Note: During the shipping process of all live rock, whether pre-cured or not, some die-back will occur. For this reason, all live rock must be cured again before it is placed in aquariums that contain fish, corals, or other marine animals.

Curing Process for Live Rock

There are many different ways to cure live rock. Two methods we recommend include:

Method A

The curing process of live rock for the established display aquarium that already contains fish, corals, or any other marine animals is as follows:

1.Rinse each piece of live rock in a small bucket of saltwater to remove any loose organic matter, debris, or sand.

2.Place the live rock in a new 30-gallon plastic garbage can. Consider adding bottom drains to the container to speed draining and water changes.

3.Completely cover the rock with freshly mixed saltwater, with a specific gravity of 1.021-1.025.

4. Provide a heater and keep the water temperature from 76-84°F. In general, the higher the temperature, the faster the curing process will occur, since it speeds the die off of unwanted organisms.

5.Create constant water movement with a power head or air stone.

6.Keep the area dimly lit to prevent algae blooms.

7.Perform 100 percent water changes twice weekly.

8.Scrub the rock with a new nylon bristle brush or toothbrush between water changes to remove any white film or dead material.

9.After 1 week, check the ammonia and nitrite levels periodically. When the water conditions stabilize and ammonia tests are zero, the rock is considered cured, and ready to be placed into the display aquarium.

Using this method, most rock will be fully cured in 3-5 weeks.

Curing Process for Live Rock (continued)

Method B

The curing process of live rock for the new aquarium that does NOT contain fish, corals, or any other marine animals is as follows:

Live rock may be used to cycle a new marine aquarium. Follow the manufacturer's directions on the installation of all filtration devices and accessories. Fill the aquarium with water and add salt to achieve the desired specific gravity of 1.021-1.025. Activate all filtration equipment, check for leaks, and set heater and/or chiller to the desired temperature of 76-84°F.

1.Rinse each piece of live rock in a small bucket of saltwater to remove any loose organic matter, debris, or sand.

2.Place the live rock into the aquarium to create a stable foundation for corals or decorations.

3.Keep the lighting system off during the cycling period in order to reduce the likelihood of undesirable algae growth.

4.Scrub the rocks periodically with a new nylon bristle brush or toothbrush to remove any white film or dead material.

5.Perform 50 percent water changes weekly while siphoning out any organic matter and loose debris that accumulates at the bottom of the aquarium.

6.Check the ammonia and nitrite levels in the aquarium weekly.

7.When both the ammonia and nitrite levels are zero, perform a 50 percent water change on the aquarium.

8.After 24 hours, check the pH of the water and adjust as needed to achieve the desired level of 8.1-8.4.

Depending on the equipment that is installed, most aquariums will cycle within 3-5 weeks using this technique.

Helpful Tips for Controlling Unwanted Pests

Before (or after) curing your newly arrived live rock, you can submerse the new rock into a bucket filled with saltwater with a specific gravity of 1.035 to 1.040 for one minute. Any invertebrates including: mantis shrimp, bristle worms, and crabs, will quickly evacuate from the rock into the bucket of water. Bristle worms still attached to the rock can be removed with a pair of needle-nosed pliers or tweezers. After removing the live rock from the bucket, you can then sort through the invertebrates in the bucket that you want to add to your system and discard the unwanted pests.

Important: Do not place live rock directly into an aquarium containing fish, corals, or other marine animals until it has been cured.

Curing Process for Live Sand

Live sand should be well rinsed in saltwater to remove any organic matter that may foul the water in the aquarium. After rinsing, the sand may be placed directly in any marine aquarium.

1.Pour the sand from the shipping bag into a new 5-gallon bucket, filling the bucket 1/2 full with live sand.

2.Add saltwater from the aquarium until the bucket is 2/3 full of water and sand.

3.Slowly stir the sand by hand until the water within the bucket becomes cloudy with debris.

4.Discard the dirty water from the bucket and place the sand back into the shipping bag.

5.Submerge the shipping bag to the bottom of the aquarium and slowly dispense the sand evenly over the bottom.

6.Repeat steps 1-5 until all of the sand has been placed into the aquarium.

By following these methods to cure live rock and sand, your aquarium will be off to a good start, and you will have created a healthy environment for the coral, invertebrates, and fish you will adding.

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