The Nitrogen Cycle

All people new to fish keeping should know the Nitrogen Cycle at least pretty well.



The gist of it:

1. Plants + Air pump + Filter = INTRODUCE OXYGEN INTO THE WATER.

2. Fish consume oxygen, produce waste called Ammonia (NH4) as well as Carbon Dioxide (CO2). Rotting food, dead plants, dead fish also produce Ammonia.

3. Bacteria called "Nitrosomonas bacteria" suck up the ammonia and changes it into Nitrite (NO2). Ammonia level drops, Nitrite levels rocket. Nitrite is just as bad as Ammonia!

4. A second bacteria called "Nitrobacter" sucks up this Nitrite and changes it to Nitrate (NO3). Nitrite levels drop, Nitrate levels climb up.

5. Plants consume Nitrates and CO2 and produces oxygen, thus repeating the cycle.



Plants --> Oxygen -->Fish --> Ammonia, CO2 --> Nitrosomonas --> Nitrite --> Nitrobacter -->Nitrate --> Plants --> Oxygen etc.




Simple enough, no?


Nitrogen Cycle Gone Wrong

Many things may go wrong during this cycling process.

1. Adding too many fish at once.
- This increases the amount of waste. Bacteria can only consume so much waste at once! Once they can no longer convert wastes, the resulting ammonia and/or nitrite poisons your fish! Symptoms of poisoning can include red gills, rapid breathing, and sick fish.

2. Not testing the water. You can't eyeball how much bacteria or waste is in the water! That's why they sell test kits. If you don't test your water, you won't know if your tank is cycled.

3. Overfeeding. Rotting food creates excess waste! Think about it. Would you want to live in a house filled with rotting pizzas and donuts everywhere you turn? Yuck.

4. Not enough patience. This process takes up to 3 months sometimes. If you're too impatient, you might ruin your progress! I personally don't like the idea of adding bacteria supplements to speed up the process. However, logically, it should be fine...right? My suggestion would be to get a nice friend to give you a used filter pad FILLED WITH GOOD BACTERIA.

5. Remove and replace water regularly to prevent buildup of nitrates. Normally, nitrates aren't bad for your fish, but if you have too much of it, it'll also be dangerous. This shouldn't be a problem if you have live plants. A good rule to follow for water changes is: a)change water when it looks cloudy b) change water daily if there's sick fish c) change 15% water weekly d) change water after medication period e) change discolored water.



NORMAL Test Kit Readings of a Cycled Tank

Ammonia - 0ppm
Nitrite - 0ppm
Nitrate - below 40ppm
PH - 7 = neutral; less than 7 = acidic; greater than 7 = alkaline