TheRock wrote:
Isn't high ammonia part of the cycle ?

Sort of. Ammonia serves as food for the first of the nitrifying bacteria you
want to develop.

Don't you need it to cycle ? If you dilute the tank with water aren't you
just
removing bacteria that moves the cycle along and prolonging cycle time ?

No, you aren't removing bacteria; for the most part, they live in the substrate
and live rock. You're removing ammonia. The fact that there is a high ammonia
level is proof that you don't have a large enough bacteria population to eat it
all. If you leave the levels as they are, the population will gradually grow
large enough to transform all of the ammonia to nitrites. Then the population
will starve and decline to whatever level can survive on the ammonia normally
introduced as urine and decay products.

If you run a 50% water change, you will remove half the ammonia. That's still
more than the existing bacteria population can handle, but the population won't
have to grow as much to reach a level large enough to transform all of the
ammonia to nitrites. Your tank will actually cycle more rapidly.

The same is true of nitrites, when the cycle reaches that point.

George Patterson
Forgive your enemies. But always remember who they are.