How to Use FritzZyme Live Nitrifying Bacteria to Cycle a Freshwater Tank
This user guide and reference is meant to help demystify the use of bacteria to establish a functional biofilter in your aquariums. Set your biofilter up for success by providing them the environment they need to thrive with these steps.
If you are trying to cycle a saltwater tank, click here.
Quick Links
Step 1: Prepare Water
Step 2: Measure Water Parameters
Step 3: Add Bacteria
Step 4: Add Ammonia Source
Step 5: Monitor Progress
Step 6: Add Livestock
FAQs
Quick Start Fish-In Cycle Guide
Quick Start Fishless Cycle Guide
The ammonia, or nitrogen, “cycle” is the process of ammonia NH3 being oxidized by Nitrosomonas sp. bacteria into nitrite (NO2-), followed by the produced nitrite being oxidized by Nitrobacter sp. bacteria into nitrate (NO3-). These processes can happen somewhat simultaneously. The rate of these processes is heavily influenced by many factors, so ensuring water parameters are optimal will reduce the amount of time to establish a sizable biological filter.
Step 1: Prepare your water
Fill your aquarium and add water conditioner (FritzGuard, Fritz Complete, Fritz A.C.C.R., etc) to remove any chlorine and/or chloramines. These two chemicals are toxic to bacteria so they must be neutralized before the addition of any FritzZyme bacteria. RO/DI water does not need any addition of a water conditioner, unless you want to add one for the benefits of a slime coat enhancer (try FritzGuard!) If you are using RO/DI water, consider replacing trace elements with FritzZyme Trace.
Step 2: Measure your water parameters
Do not skip this step! Your water parameters are very important to maintaining a healthy population of nitrifying bacteria, and giving them the tools they need to convert the toxic ammonia and nitrite before it can build up and harm any livestock in the system. Most issues with bacteria performance can be attributed to one of these parameters not being satisfied.
Temperature: The bacteria can work their fastest in temperatures from 77-86 F (25-30 C). Below this range, you can expect the bacteria to continue to work, but the nitrification process will become slower as the environment gets colder.
pH: The average pH range for optimal nitrification is 7.3-8.0. Above or below this range, you can expect the bacteria to continue to work, but the process will become slower as the pH approaches 6.0. Nitrification is completely inhibited below pH 6.0.
Quick Fix: If your pH is below 6.0 and you need to raise it, try our Fritz pH Higher.
Note: all ammonia in a system that is below pH 6.0 is ionized into its non-toxic form of ammonium (NH4+). Ammonium is safe for livestock and does not pose a threat. As pH is raised above 6.0, the safe ammonium WILL be converted to toxic ammonia and can quickly kill any livestock if not addressed with bacteria, a water change, or an ammonia-binding product like Fritz A.C.C.R..
Alkalinity (KH): Alkalinity is a crucial ingredient in the conversion of ammonia to nitrite. A small amount of KH is consumed during this process, and can quickly become a limiting factor if not maintained above a minimum level of 4.5 dKH or 80 ppm KH. Again, over time this parameter will naturally decrease, and must be addressed with a product that raises KH, or a water change using source water with the proper KH level. A low KH level can also lead to instability of pH. A large swing in pH in a short period of time will negatively affect your livestock, as well as your biological filter.
Quick Fix: If your KH level has dropped too low, raise it with Fritz RO Recharge, or Fritz Rift Lake Cichlid Buffer.
Phosphate: The phosphate level should always be maintained above 0 ppm. Phosphate is necessary for Nitrobacter sp. bacteria to convert nitrite to nitrate, and is consumed in the metabolic process. If it is depleted, nitrite conversion will stop.
Quick Fix: Increase phosphate with a phosphate-based buffer like Fritz pH Neutralizer, or a water change with dehclorinated tap water.
Salinity: Freshwater systems should use FritzZyme 7 or FritzZyme Turbo Start 700. Saltwater and reef systems should use FritzZyme 9 or FritzZyme Turbo Start 900. The bacteria strains in each formula are optimized for either freshwater or saltwater and are not interchangeable.
Most brackish systems should use the freshwater formulas of bacteria - FritzZyme 7 or Turbo Start 700. These freshwater strains of bacteria are fully functional in systems from 0 - 6 ppt (1.000 to 1.0045 sg). Above this range, you can expect the bacteria to continue to work, but the nitrification process will become slower as the environment gets saltier up to 15 ppt (1.011 sg). If your system is above 15 ppt, we recommend to switch to the saltwater formulas - FritzZyme 9 or Turbo Start 900.
Step 3: Add Bacteria
Fritz offers two formulas of nitrifying bacteria to assist in a variety of situations — our standard FritzZyme 7 and our concentrated FritzZyme Turbo Start 700. Both products have the same bacteria species and work in the same way. The only difference is how many bacteria are in each dose. Either formula can work in most situations, but may require adjustment of dose or time period to become fully established.
Establishing a new biological filter: Fritz recommends using our concentrated Turbo Start 700 when establishing a biological filter on a new tank, or re-establishing a biological filter after a crash or medication has reduced the nitrifying population below the sustainable threshold level. New systems can naturally be colonized by nitrifying bacteria, but the process is very slow and can be unpredictable. Using seeded filter material, substrate, or water from established tanks delivers only a very small amount of bacteria, and can take weeks to reach a population size necessary to support livestock in a new system.
How often do I dose? One application of Turbo Start 700 is concentrated enough to fully establish a biological filter capable of supporting livestock.
Can I add more? Yes. If you will be overstocking the system or expect a higher than usual amount of ammonia to be produced (say from overfeeding), the bacteria can be dosed repeatedly at any time.
Maintaining or boosting an existing biological filter: Fritz recommends our standard bacteria formula, FritzZyme 7, for all other situations where increasing the biological filter would benefit your system:
- After maintenance or filter cleaning to replace any lost bacteria
- When adding new fish to an established system to support the additional bio load
- During or after medications/treatments that may inhibit the bacteria
- Regularly dosing during a slow fishless or fish-in cycle
How often do I dose? Apply FritzZyme 7 bacteria in at any time, when needed. You can determine when to reapply by monitoring the ammonia and nitrite levels regularly.
Step 4: Add an Ammonia Source
The bacteria species in FritzZyme nitrifying bacteria formulas require ammonia and nitrite to survive. A cycle can not start until this step has been taken. This can be achieved in a few ways:
Adding fish/livestock: Adding fish and beginning to feed them normally will kick off the production of ammonia, and subsequently nitrite, through normal respiration. This is the quickest way to establish your bacterial population to the proper size, and support it passively.
Adding chemical ammonia: Dry or liquid ammonium chloride, such as Fritz Fishless Fuel, is an easy way to control the amount of ammonia added to the system and monitor the progress of the cycle.
Adding organic matter: Also known as “ghost feeding,” this method uses organic material as the ammonia source. This organic material often comes from fish flake or pellet food, or a larger item like a frozen shrimp. Ammonia production is hard to control with this method, and can also take a lot longer than the others available, causing the bacterial population to be smaller and less stable.
Note: The ammonia concentration during the cycling process does not need to be at a specific level. Any detectable level below 4 ppm is sufficient to start the cycling process.
Step 5: Monitor the Cycle Progress
Every system will proceed through the ammonia cycle at its own pace. The only way to know what stage the cycle is in is through regular testing of the water parameters.
Testing Ammonia: The ammonia concentration during the cycling process does not need to reach or remain at a specific level. Any detectable level below 4 ppm is sufficient to start the cycling process. Try the Fritz Ammonia Test Kit!
Testing Nitrite: Nitrite is directly produced from ammonia being oxidized. The level of nitrite during the cycling process will vary, as it can increase from bacteria processing ammonia, but simultaneously decrease from bacteria processing the nitrite into nitrate. Try the Fritz Nitrite Test Kit!
Testing Nitrate: The nitrate concentration will indicate if the cycle is progressing as expected. The presence of nitrate indicates that the bacteria are performing properly and the tank is cycling. The amount of nitrate at the end of the cycle does not need to reach any specific level. When the nitrate concentration builds to 20 ppm or more, a partial water change is recommended. Try the Fritz Nitrate Test Kit!
Once your bacteria are managing the ammonia and nitrite and keeping them at undetectable levels, the tank is considered “cycled.” On average, FritzZyme 7 will become established in 7-14 days. FritzZyme Turbo Start 700 can become fully established in 3-4 days on average.
Step 6: Stocking Your System
When you are satisfied that your bacteria have become established, begin to introduce your fish and other livestock.
Once your bacteria are managing the ammonia and nitrite and keeping them at undetectable levels, the tank is considered “cycled.” On average, FritzZyme 7 will become established in 7-14 days. FritzZyme Turbo Start 700 can become fully established in 3-4 days on average.
FAQs
I used Turbo and added fish right away, and I never saw any ammonia or nitrite. Is this normal?
Yes, the bacteria concentration in Turbo start is high enough to immediately process ammonia and nitrite produced by your fish, preventing a buildup of ammonia and nitrite. You may not see these “spikes” in this situation like you might in a fishless cycle. This is exactly how a tank that is considered “established” operates.
My ammonia level is zero, but I have high nitrites. What do I do?
This may be due to a low phosphate level causing “phosphate block.” We recommend doing a partial water change. You can add additional bacteria if you desire. If you do not anticipate adding fish to the system within 48 hours of the ammonia level reaching zero, add a partial dose of ammonia (0.5 to 1.0 ppm) and continue to monitor. Repeat these steps as necessary until ammonia and nitrite both reach zero and you will add fish within 48 hours.
My ammonia level is not going down. What do I do?
This may be due to a low KH level, or a low pH level. Adjust either/both if needed according to the guidelines outlined in Step 2 above. If these are in place and you still are not seeing a reduction, check your test kit for accuracy and check the expiration date of both the test kit and the bacteria.
The bottle I ordered was warm when it arrived. Is it still good?
Yes. The bacteria will stay viable in temperatures up to about 95F for many days. You can use it right away or place it back in refrigeration until you are ready to use it.
I opened the bottle and it smelled bad. Is the bacteria still good?
Yes, the odor is completely normal. Different batches odors will vary quite widely and the presence or absence of an earthy odor does not indicate that the bacteria are bad or won’t work as expected.
I want to start a brackish water tank, which formula do I use?
Most brackish systems should use our freshwater formula. If you plan on having a brackish system above 15 ppt, switch to the saltwater bacteria formulas.
Does the bacteria work in cold water?
Yes, the bacteria will be active even in very cold water. Due to the lower temperatures, activity will be significantly slower, however. Just give them extra time, or increase your dose to speed up the performance of the bio filter.
Can I use the freshwater and saltwater formulas interchangeably?
No. The saltwater and freshwater formulas have been optimized for their respective intended environments and will not have the desired effect when interchanged.
Fish-In Cycle Quick Start Guide
- Dechlorinate any tap water used
- Add desired amount of bacteria, the normal dose on the Turbo Start label is plenty
- Add fish in to the tank within 24 hours of adding the bacteria
- Monitor ammonia and nitrite levels
- Detoxify any ammonia and nitrite with a detoxifier (like Fritz Complete) if needed
- Water changes can be done any time 4-5 days after you’ve added in bacteria
- Otherwise feed normally and do maintenance on a normal schedule
- Add more bacteria in at any time if desired. We recommend a dose of FritzZyme 7 or partial dose of Turbo Start 700 when adding new fish
Fishless Cycle Quick Start Guide
- Dechlorinate any tap water used
- Add desired amount of bacteria, the normal dose on the Turbo Start label is plenty
- Add desired amount of ammonia in to the tank within 24 hours of adding the bacteria, up to 4 ppm
- Monitor ammonia, nitrite, and nitrate levels
- Water changes can be done any time 4-5 days after you’ve added in bacteria, we recommend 25% weekly until the cycle is finished
- Add more bacteria in at any time to speed up the cycle
- Add more ammonia if the ammonia level gets to zero and you are not ready to add fish. We recommend a half or quarter dose of Fritz Fishless Fuel
- Once the ammonia and nitrite levels are at or very near zero, add fish
- Monitor the levels with your test kits and add more bacteria in as desired