The length of time a filter can be used before it needs cleaning, usually including cleaning time. The cycle process generally takes up to eight weeks for your water to reach an acceptable level of purity. It is wise until then to not utilize the product water for any sort applications such as consumption, showering, or pet aquariums. Utilizing unclean water for your pet fishes might be hazardous as high levels of nitrate and ammonia can lead to their serious harm. Once the water has been sufficiently cleaned, adding your fish a few at time would be more prudent since placing too many of them at once might make your tank have to cycle again. However, only adding them a few at a time will only increase bacteria growth for a short period of time with no effects on your pet fishes.