A first-time aquarium owner, Ruben Gomez, posted online this week seeking advice after adding fish to a newly established tank without first cycling it. The question, posed on a social media platform, quickly drew attention from aquarium hobbyists concerned about the welfare of the fish.
Cycling a tank refers to the process of establishing beneficial bacteria that convert harmful ammonia and nitrite – produced by fish waste – into less toxic nitrate. Without these bacteria, ammonia and nitrite levels can quickly build up, poisoning fish. Experts recommend completing this process before introducing any aquatic life.
Gomez’s post prompted a flurry of responses, with many advising immediate and frequent partial water changes to mitigate the effects of ammonia and nitrite buildup. One user on the FishLore Aquarium Forum described a similar situation, detailing how a previous attempt to follow advice from a family member regarding fish care resulted in the death of multiple bettas, likely due to ammonia poisoning. The user, identified as MermaidMelody, detailed researching the nitrogen cycle and realizing the initial advice was detrimental to the fish’s health.
The practice of adding fish to an uncycled tank to “instantly” start the cycle, as suggested by an employee at a local fish store to a Reddit user, is controversial. While the fish waste will indeed produce ammonia, initiating the cycle, it does so at the expense of the fish’s health. The Reddit user, posting in the r/ReefTank forum, described being advised to add a pair of yellowtail damsels to their 250-liter tank for this purpose.
A video posted to YouTube details methods for safely adding fish to an uncycled aquarium, emphasizing the need for tools and a careful approach to maintain water quality. However, the long-term viability of this method remains a concern within the aquarium community.
Experts agree that fish can survive in an uncycled tank for a limited time, but the duration varies depending on factors such as the number of fish, the size of the tank, and the amount of waste produced. Frequent water changes are crucial to dilute the toxic compounds, but even with diligent care, the stress on the fish can be significant. A post on FishLore noted that a 5-gallon tank could be considered overstocked, even with comparatively low-bioload species like shrimp and snails, further exacerbating the issue.
