Back to Coral Reef Aquariums Live Rock

How To Cure Live Rock


We Sell Live Rock from $3.99lb

You need the following equipment:

  1. appropriate size container
  2. protein skimmer (it will get a major workout)
  3. powerheads
  4. heater
  5. saltwater
  6. a small scrub brush
  7. ammonia, nitrite, nitrate test kits

The basic method is as follows.

  1. Scrub off any sponges and soft corals that have turned black
  2. pH should be 8.2-8.4
  3. Salinity should be  1.023-1.025
  4. Keep lights off for 7-10 days to avoid an algae bloom (high nutrients)
  5. Water temperature should be (74-80oF)
  6. No water changes until Ammonia and Nitrites tests both read zero. Then do a 50-75% water change, vacuuming the loose sediment.
  7. Position powerheads for maximum water movement within the container
  8. Provide plenty of oxygenation in the water (done by skimmer which will need frequent cleaning)

The curing process will take 2-4 weeks to cure UNCURED Live Rock depending on the amount of die-off on your rock and the effectiveness of your protein skimmer. A simple but very effective treatment for eliminating unwanted critters in your Live Rock is to dip each piece in a bucket of very saline water (SG 1.030) for a few moments.  Mantis shrimp will quickly evacuate the rock.  Bristle worms will also crawl out and can be pulled from their holes with a pair of tweezers. Coral Reef Aquariums sells only CURED Live Rock, which means we process the rock prior to offering it in our tanks.


Beneficial Bacteria and Aquarium Bio-Load

Many hobbyists do not really understand the relationship between nitrifying/denitrifying bacteria (we'll call them beneficial bacteria) and the nitrogen cycle in their aquariums. This page is intended to provide a basic knowledge of this very important aspect of our hobby.

You may have noticed that new hobbyists struggle with a lot of deaths in the first few months of setting up their first aquarium but, after several months, they seldom experience any deaths. This is usually chalked up to the hobbyist having gained some experience. That is only half of the story. The other half is that the aquarium has reached its 'point of equilibrium' where the quantity of beneficial bacteria is sufficient to support the biological functions (bio-load) of the aquarium's inhabitants.

The bodily functions of fish and other inhabitants produce ammonia waste. Prolonged exposure to ammonia is toxic to fish and corals. Beneficial bacteria convert ammonia waste into nitrites (also toxic) and then to nitrates. Complete elimination of nitrates is virtually impossible but fish and corals can tolerate low levels of residual nitrate in the aquarium system. Water changes help keep nitrates at acceptable levels.

Changes in Bio-Load
Once an aquarium has achieved equilibrium, any life forms that are added (or removed) will take it out of equilibrium. The quantity of beneficial bacteria will always increase or decrease to match the amount of ammonia produced within the aquarium.

If a new fish is added, this increases the bio-load and raises the ammonia levels since there are not enough bacteria in the system to handle the increased ammonia. With this additional food source, the bacteria will begin to multiply rapidly and will increase enough to once again reach the point of equilibrium. The reverse happens when an ammonia producing life is removed from the system. The bacteria's nutrient source is reduced and so its population must decline until equilibrium is achieved once more.

Every change in the bio-load of your aquarium causes a new 'nitrogen cycle'. The size and duration of the cycle is directly related to the size of the change in the bio-load. This is often referred to as an 'ammonia spike'.


Live Rock
A very common misconception about Live Rock is that adding cured rock to an aquarium will not cause an increase in ammonia. This is incorrect.

"Any addition to the bio-load of an aquarium
will cause an increase in ammonia".

It doesn't matter if you are switching cured Live Rock from one of your own aquariums or if you have made a new purchase. Newly introduced Live Rock will upset the equilibrium of your system and it must be re-established.

The value of Cured Live Rock is threefold:

  1. it produces a much smaller ammonia spike than would be seen using uncured rock
  2. it introduces a huge amount of beneficial bacteria to the aquarium
  3. the ammonia spike lasts a very short time compared to uncured rock

The hobbyist should always remember that adding a large quantity of Live Rock (or any other life form) will cause proportionate increases in ammonia levels within the system. The more Live Rock that is added, the more beneficial bacteria that must (and will) be produced to bring the system back into equilibrium. Depending on the amount of additional bacteria needed, this can take a few hours to several days.  If possible try and purchase “Cured” live rock and let someone else do the work of curing like we do here at Coral Reef Aquariums.


Your marine aquarium is more than just fish and corals - it is a complete living system. All of the elements of the system interact together and a healthy aquarium is completely balanced. It is always best to make small, incremental changes to your system rather overtax it with a large one.

Coral Reef Aquariums

Sweetwater Square

895 Fox Valley Drive

Longwood, Florida  32779

Ph. 321-972-6970