It's a tough call. The only way to know if your tank is cycled is to
test for nitrate, which I realize you haven't got the test to do.
Essentially, the process would have showed ammonia spiking and falling
followed by nitrite spiking and falling and then finally a slow incline
of nitrates. So, if your tank has gone though the nitrogen cycled you
would be left with 0 ammonia, 0 nitrites and measurable nitrates. Doing
full 100% water changes and fully changing the filter media could be
hampering your ability to cycle your tank. This coupled with the small
water volume can make the cycle difficult to maintain. Small aquariums
are always a bit more work in terms of monitoring water parameters
compared with their larger counterparts. Like you, I have several small
betta tanks and have dealt with similar problems.

Best of luck.

wrote:
I have a 2 gallon tank with a filter which I keep a Betta and a clump
of Java moss in. What I usually do to take care of the water is change
a quater of the water every week and then do a complete water change
every 4 weeks. Change the filter medium every 2 weeks.

Well its been about 3 weeks since I changed his water completly, and I
just tested his amonia and nitrite levels. They didn't seemed very low
if not none at all. Is it possible that this tank has been cycled? I
don't have a test for the nitate levels so I"m not sure on those.

Is it possible that the plant is sucking up all the amonia and nitrites
so there is none of those, so its not really cycled but is acted like
one?

Well thanks for any help you can give.

-- Nathan