Not sure if I know what I'm doing!

[LittleBettaFish]

You can cycle tanks smaller than a 5 gallon. Go on to any planted tank forum and these people have some seriously expensive and sensitive species of fish living in small tanks that have been completely cycled.

What you need in a small tank is a filter with a large surface area so as much bacteria as possible can establish itself. This is important because of the rate in which ammonia and nitrite build-up in small aquariums. I also recommend using fast-growing live plants such as floaters or stems as these help stabilise your cycle by consuming excess ammonia and nitrates.

If you are not comfortable with the idea of cycling your tank, simply don't put in a filter and stick with doing regular water changes instead. While cycling is more work at the start, once your cycle has established itself, your tank will not need as much regular maintenance as one that is uncycled.

However, for those new to the concept, it is sometimes easier just to do 50-100% water changes every few days than to have be fiddling around with test kits and water changes for 4-6 weeks.

[TeacherTeapot]

But would putting them in an uncycled environment cause them any kind of extreme stress? I want my new friend to stay with me as long a possible.

[aokashi]

Doing regular maintainance and having everything fall in to a pattern will ensure that your fish lives as long as possible.

However some petstore fish may already come with underlying illnesses. Best to buy the healthiest fish possible at the start :)

like LBF said, having floaters like duckweed will also ensure that your water parameters remain stable :)

[LittleBettaFish]

Not if you do appropriate water changes. This is why it becomes important that you have a test kit for ammonia. You ideally should have a level of 0ppm of ammonia at all time (won't worry about nitrite as that should usually only crop up in cycling tanks). If you test your ammonia and it is at .25ppm it is best to do a 100% water change. If you muck around and do 50% water changes you tend to still end up with ammonia present.

What I do with uncycled tanks is test daily and then when I get a reading of ammonia, do an immediate water change. I then let the tank sit for the number of days that it took to register an ammonia reading, and then test again to see if a water change is needed. This way you can set up a schedule of how often you need to do water changes and how much water needs changing out.

The stress of doing a large water change is probably less than the stress caused by continued exposure to low levels of ammonia.

[TeacherTeapot]

The tank I was looking at getting has a built in filter, so wont it then cycle itself eventually?

[LittleBettaFish]

Yes it most probably will. But if you are doing a fish-in cycle you are going to have to keep both your ammonia and nitrite at '0ppm' to avoid harming your fish.

However, even though your test kit may measure at 0ppm, there is still ammonia present that commercial test kits are usually not sensitive enough to register. These trace amounts are enough to feed your bacteria, but it does mean that the cycling process takes a little longer than if you were doing a fishless cycle, where you can tailor your conditions to maximize the growth of bacteria without worrying about livestock.

[TeacherTeapot]

So how long do you think a 2 gal tank will take to cycle?

[aokashi]

many factors can affect a cycle. PH, temperature... etcetc. the only way to know for certain is to use a test kit and test your water during the cycling process to know for sure when the cycle establishe.

[Hallyx]

Remember, cycling the tank is not for the keeper's convenience, but to provide the purest waterr for the fish.