Is this normal?

The levels are okay, a bit on the high side for having fish in the tank. Perhaps it may be easier to do 30% water changes every day or so. Water changes at this stage are a must to keep your fish healthy.

The bacteria levels are starting to build up, as is shown by the production of nitrites.

As for the ammonia not changing, exactly what do you add when you do water changes as far as chemicals go? And what sort of test arte you using?

Sometimes test kits can go bad. If you can, try taking a water sample to your LFS and see if they will test it and compare the results to yours.

If you're changing water every other day without a significant colony, that may be sufficient time for the ammonia levels to rise again.

Do as TKOS suggests and switch to daily water changes. You may even opt to twice daily once in the morning and once at night.

How much/often are you feeding? Excess food will produce ammonia and ample food=ample wastes, cutting back feedings is another point to ponder.

I doubt that it's your test kit. Most kits are based on fairly robust chemistry. Although for lab purposes the reagents have much shorter lifetimes, hobby kits work with much lower levels of precision, so degradation is less important. Nonetheless, bad batches do exist and if you have reason to doubt your kit, getting a second test done is useful. Carry the water in a sealed container away from the light and, if possible, kept cool, or at least not warmed.

You can also test your tap water. There should be 0 ammonia from your tap, but you can verify this with your water company. Get a water report from them, why not know exactly what's going into your tank? You're paying them to do the tests for you, after all, and they've got much more sophisticated instrumentation.

Would changing that much water so often slow down the cycle because the ammonia is taken out that the bacteria need to feed off of?

Kim

In a word, yes. But once the fish are in there, your first thought must be to preserving their health and minimizing the damage done.

In more detail, maybe, maybe not. Depending on how well established the colony is, it may not matter. If the colony is big enough to be food limited, then yes, but on the other hand, if it was, you wouldn't be detecting ammonia.

As long as there is some ammonia the cycle will continue. Don't forget that the reason ammonia registers on the test kits is that there is too much ammonia for the bacteria, and it doesn't grow that speedy.

No. Changing water will not slow the cycle one iota. If you've got measurable ammonia, it's like two rabbits and a warehouseful of carrots. If you truck out half the carrots, the rabbits will still breed like rabbits.