So, you have just brought home your brand new aquarium and have finished setting it up.  The gravel is in place. The tank is filled to the brim with water that has reached a comfortable temperature for the type of fish you are planning on keeping.  Now it’s time to go to the local fish store and purchase your new aquarium occupants. 

Whether you are stocking a small 10 gallon, 55 or a larger 100 gallon plus size aquarium, you may feel a need to immediately fill the tank with lots of fish. But putting a large population of fish into a brand new aquarium is a recipe for disaster.  Every aquarium must go through a cycling process or “New Tank Syndrome”. 

Beneficial bacteria are what helps keep fish alive. The bacteria will eat away at the toxic ammonia that fish produce as waste.  The bacteria convert the toxic ammonia to a slightly less toxic nitrite.  The nitrite is than converted to scarcely toxic nitrate.  Nitrate is taken out of the aquarium by water changes and absorbed by plants and algae. In a new aquarium with no established bacteria, the fish produce ammonia and then start breathing that ammonia causing death. It takes 4-6 weeks for these bacteria do develop naturally after fish are added.

In order for these Nitrifying bacteria to get started in your aquarium, you must feed it a bit of ammonia.  Having the tank running empty for a month will not accomplish anything. One way a person can help break in their new aquarium is by adding a handful or two of gravel from an already establish aquarium.  Sprinkle the gravel on top of the new gravel or by placing it in a mesh bag and inserting it into the filter area.  There are also products available that help speed up the cycling process.  These products can be very helpful in a new tank but I do not suggest using them as a sole substitute for patience and careful cycling.

When you do stock the aquarium, start with inexpensive and hardy fish.  Medium tetras or barbs can be a good first choice for the aquarium. Fish that you should not start the aquarium are any types of catfish or algae eaters.  These fish should be avoided in new tanks not only because there is little to no food for them yet, but since these fish are bottom dwellers, where the ammonia is more concentrated and there is less oxygen, they are more susceptible to toxic ammonia.

In saltwater aquariums, live rock is a perfect seed for beneficial bacteria.  Just add several pounds of live rock to your new aquariums and in two to three weeks the aquarium will be ready for your new fish.

-Kevin Ellwanger