Cycling Your Aquarium

A Guide for Fish, Axolotls, and Other Aquatic Pets 

Starting a new aquarium is exciting, whether you’re keeping fish, axolotls, or other aquatic animals. But one of the most important steps many new keepers overlook is cycling the tank. Properly cycling your tank ensures a healthy, stable environment for your pets and prevents stress, illness, or even death. At Roxy’s Pet Shop, we guide you through the process so your aquatic friends can thrive.

Cycling is the process of establishing beneficial bacteria in your aquarium that convert harmful ammonia from waste into nitrites and then nitrates, a process called the nitrogen cycle. Without these bacteria, ammonia and nitrites can quickly reach toxic levels and harm your aquatic animals.

• Protects Your Animals: Ammonia and nitrites are highly toxic to fish and amphibians like axolotls.
   
• Stabilises Water Chemistry: A cycled tank maintains safe levels of nitrogen compounds.
   
• Prevents “New Tank Syndrome”: Avoids sudden die-offs common in newly set up tanks.
   

• Rinse your substrate, decorations, and equipment with clean water.
   
• Fill the tank with dechlorinated water.
   
• Install filters, heaters, or other equipment according to your tank’s needs.
   

There are two main approaches:

a. Fishless Cycling (Recommended for axolotls and sensitive species)

• Add an ammonia source (pure ammonia or fish food) to feed beneficial bacteria.
   
• Test water daily for ammonia, nitrites, and nitrates.
   
• Wait until ammonia and nitrites drop to 0 ppm and nitrates rise—usually 4–6 weeks.
   

b. Fish-in Cycling (Not ideal for axolotls)

• Add a few hardy fish and allow them to produce waste to feed bacteria.
   
• Requires frequent water changes to keep ammonia and nitrites at safe levels.
   

Important: Axolotls are very sensitive to water quality, so fishless cycling is strongly recommended.
 

Use a reliable aquarium test kit to check:

• Ammonia (NH₃/NH₄⁺)
   
• Nitrite (NO₂⁻)
   
• Nitrate (NO₃⁻)
   

Beneficial bacteria are established when ammonia and nitrite levels consistently read 0, and nitrates are present.

Once the tank is cycled:

• Add fish or axolotls gradually to avoid overwhelming the bacteria.
   
• Continue regular water testing during the first few weeks of stocking.
   

• Don’t rush: Cycling takes time; patience prevents long-term health problems.
   
• Use live plants: They help absorb nitrates and improve water quality.
   
• Avoid overfeeding: Excess food increases ammonia levels and slows the cycle.
   
• Consider beneficial bacteria products: These can speed up the cycling process.
   

• Fish: Most hardy freshwater fish can tolerate fish-in cycling, but sensitive species should wait until the cycle is complete.
   
• Axolotls: Must always be added to a fully cycled tank; even small amounts of ammonia or nitrite can be fatal.
   
• Other aquatic animals: Shrimp, snails, and delicate amphibians also need a fully cycled tank to thrive.
   

At Roxy’s Pet Shop, we stock all the equipment, test kits, and bacterial supplements you need to cycle your tank safely. Our team can help you plan a smooth cycle for your fish, axolotls, or other aquatic pets so they have the best start in their new home.