A cycled tank needs less upkeep and is generally, imho, healthier. Cycling a tank develops good bacteria. Fish waste and left over food turn into toxic ammonia in a tank. Once you have the bacteria present to change ammonia to nitrite and then nitrite to nitrate, you will have to do fewer water changes. Ammonia and nitrite are toxic to fish. Nitrate, much less so. In a cycled tank the bacteria change the ammonia to nitrite and then nitrite to nitrate all on their own. So your fish aren't exposed to toxic ammonia and nitrite and you only have to make water changes to remove some of the nitrates as they build up.

 

http://www.bettafish.com/showthread.php?t=115758 Here's a link to the recommended water change schedule. You can see that cycled tanks are cleaned differently and never need 100% water changes. Live plants help a bit, too, but you probably need a lot of them to notice a difference.

 

I always figured my tanks were to small since mine range for 1.7-2.5 gallons

 

I cycled my first tank - a 1.5 Tetra Cube, in 4 weeks. I also have one 1.4g foster tank that I accidentally cycled. No such thing as too small really.

A fully cycled tank is the safest, least stressful environment for fish. I always prefer to fishless cycle my tanks before I put any living thing in it. We are fortunate our Bettas are hardy enough to withstand an uncycled tank, or one that is still cycling. Many other species out there cannot

 

Technically there is no such thing as a "too small" tank to cycle. Cycling refers to the fact that you have colonies of beneficial bacteria that help with your water quality living in your tank and on your filter media.

 

Yes, the smaller the harder to cycle (most of the time) but all tanks that are filtered can be cycled.

 

Is that true? My 5g just cycled without a filter. It has gravel, a large piece of mopani wood, a bunch of plants and an aerator. I read that actually more bacteria live in the gravel than in the filter, though of course they live in the filter too. But my understanding was that bacteria will live anywhere, as long as they have oxygen and water movement.

 

I thought so... But that does make sense... So I'm not sure.

 

While it does make maintenance easier, that is not the most important reason for cycling.

A cycled tank provides the best water quality for your livestock <period> It keeps ammonia at 0.0ppm at all times, even between water changes. Only a heavily-planted tank offers the same protection. Most keepers use plants and the cycle together -- it just works better that way, especially in smaller tanks.

Any volume of non-toxic water will support the growth of cycling bacteria. IF there is enough surface area (filter, substrate, decor/plants) for a big enough colony, and enough oxygen, the bacteria will grow to oxidize all the ammonia produced by the stock. In other words: any size tank can -- and arguably should -- be cycled. In fact, you have to work to prevent it.

CYCLING: the two-sentence tutorial

How big a colony grows in the substrate compared to that in the filter is the object of much conjecture and discussion. Even if more bacteria lives in the substrate, the filter bacteria are exposed to more ammonia. What is known is that, in a mature established cycled tank, the colony (as a biofilm) distributes and arranges itself throughout the system in such a way as to completely oxidize all ammonia produced -- and in the most efficient manner.