An aquarium is considered safe for livestock once the nitrogen cycle has completed, and the natural biological filtration has been established and is working.
The nitrogen cycle converts toxic ammonia to nitrate by oxidation through bacteria. These bacteria make the water safe for fish, a process that starts as soon as ammonia is present.
The source of ammonia in a fish tank usually is dissolved organic waste (uneaten fish food, dead plant matter, etc), as well as dissolving fish excrement.
When first establishing a new fish tank, it is common for ammonia and nitrite to reach lethal levels. Fish loss during cycling is therefore quite common.
Fishless cycling is an alternative without risking and sacrificing fish in the process.
Fishless cycling utilizes ordinary household ammonia to get things started.
Use a common eyedropper to (daily) administer the ammonia to the fully setup tank as follows:
- 5 drops of ammonia per 10 Gallons of water to start
- 3 drops of ammonia per 10 Gallons as soon as nitrites are detectable
- 3 drops of ammonia per 10 Gallons until both ammonia and nitrite are undetectable
Cycling an aquarium usually takes 3-6 weeks. Starter bacteria or seeding material from mature tanks will speed up the process.
Test kits for ammonia, nitrite, and nitrate are required to determine the completion of the cycle. Once complete, fish can safely be introduced to the tank.
Note: Use water conditioners to remove chlorine only. Do not use conditioners with ammonia removers, as they will defeat the purpose.