Water Quality Deterioration:
* Ammonia build-up: Fish excrete ammonia as waste, which is highly toxic. Without a filter, ammonia levels will quickly rise, poisoning your fish.
* Nitrite build-up: Bacteria convert ammonia to nitrite, another toxic compound. This can also reach dangerous levels without a filter.
* Nitrate build-up: Nitrite is further converted to nitrate, which is less toxic but still harmful in high concentrations.
* Lack of oxygen: As waste and organic matter decompose, they consume oxygen from the water. Without a filter to aerate the water, oxygen levels will decrease, leading to suffocation.
* Algae growth: Lack of filtration allows organic matter to build up, leading to excessive algae growth. This blocks sunlight, creates an imbalance in the ecosystem, and can harm your fish.
Health Issues for Fish:
* Stress and disease: Poor water quality causes stress on fish, making them more susceptible to infections and diseases.
* Reduced lifespan: Poor water conditions lead to a shortened lifespan for your fish.
Unpleasant Tank Environment:
* Cloudy water: Without filtration, the water will become cloudy and murky due to the build-up of waste and organic matter.
* Unpleasant odor: The decaying organic matter will produce a foul odor.
Overall:
A fish tank filter is essential for maintaining a healthy and thriving environment for your fish. Without one, your fish are at risk of serious health issues, shortened lifespans, and even death.
Note: Even if you have a small tank, you should still use a filter. There are filters specifically designed for smaller tanks.