Ammonia in new fresh water tank

Question
We started with a new 26 gallon fresh water tank last year and had ammonia problems from the start.  Likely overfed fish was thought to be the problem.  Did numerous water changes and gave up last summer after months of trying.  Had our tap water (well water) tested for ammonia within a few hours of collection, and it came up fine.  I drained the tank, rinsed all the gravel, plants, etc. and started over again last week with a tank of fresh water.  Bought an ammonia indicator that remains in the tank and initially, the ammonia level was below the measurable range.  Four days after filling the tank and having it cycle, our ammonia level is at the caution level!  What is causing this?  SHould I have thrown out all the gravel?  Are the aquarium plants and decor (tank approved) causing this?  Would my tap water (well water) have nitrates that chemically degrade into ammonia after several days?  

Answer
Your water is cycling and its normal for the ammonia to go from nothing to a high level, with a tank like yours it should correct itself in a few days maybe a week you should notice it lowering. You can also take a clean unworn nylon and cut off the tip and place ammo chips in it (use a rubber band to close the nylon) and set that in your filter to help filter out the ammonia, regular carbon usually will not take out the ammonia but the ammo chips will and it will not cause any harm. No, you did not need to throw away the gravel, the plants are not causing the issue or decor. You tap water may be turning into ammonia, again you can use the ammo chips as I suggested earlier and you can use a product called aquasafe, basically this liquid will neutralize the water in the tank, this a great product to use when water changes are done, new fish are added as it also helps ease stress in fish. If there is anything more I can do please feel free to contact me. Best of luck, happy fish keeping.