02/01/2026
How to set up New Tank
During the reef tank cycling period, your main tasks are to establish the beneficial bacteria colonies needed for the nitrogen cycle by providing an ammonia source and monitoring water parameters regularly.
Patience is crucial; the cycle typically takes 4 to 8 weeks, and attempting to rush it by adding livestock too soon is a common mistake that can lead to fish loss.
Key Steps and Actions
Set up all equipment: Ensure all pumps, filters, heaters, and protein skimmer (though some turn the skimmer off initially) are running correctly. The bacteria need a place to colonize, primarily on your live rock (or dry rock) and filter media.
Add a source of ammonia: Since there are no fish yet (fishless cycling is highly recommended), you must manually introduce an ammonia source to feed the initial bacteria growth.
Use a pure ammonium chloride solution (like Dr. Tim's Ammonium Chloride) and dose to a specific level, usually 2-4 ppm.
Alternatively, you can place a small piece of unseasoned, raw table shrimp in the tank and let it decompose. Remove it after 72 hours.
Dose beneficial bacteria (optional but recommended): To significantly speed up the process, add a quality, bottled, live nitrifying bacteria product (such as FritzZyme TurboStart 900 or Seachem Stability) to "seed" the tank.
Monitor water parameters daily: Use a reliable saltwater test kit to track ammonia, nitrite, and nitrate levels.
Expect a spike in ammonia, followed by a drop in ammonia and a spike in nitrite.
Finally, the nitrite will drop to zero, and nitrate will become detectable and begin to rise.
Keep a log of your test results to track progress.
Maintain stable environmental conditions:
Keep the temperature stable, around 77-84Β°F (25-29Β°C).
Ensure salinity levels are correct (around 1.024-1.026 specific gravity).
Keep the lights off during the initial cycle to minimize nuisance algae growth.
Avoid large water changes: Do not perform large water changes during the main cycling phase as this removes the ammonia source and the developing bacteria colonies, prolonging the cycle. Top off with fresh RO/DI water daily to account for evaporation and maintain stable salinity.
When the Cycle is Complete
Your reef tank is cycled when both ammonia and nitrite consistently read zero for several consecutive days (24 hours after dosing ammonia if doing a fishless cycle), and nitrates are present.
Perform a large water change: Before adding any livestock, do a 25-50% water change to reduce the accumulated nitrates and replenish essential elements.
Add your first livestock slowly: Start with a few hardy fish and/or a small clean-up crew (snails and crabs). Wait at least a week or two between additions to allow the bacteria population to adjust to the increased bioload.
