The Fishless Aquarium Cycle

I get a lot of requests for help on this one. And it is always the same problem. So I will start with that. It is not necessary to build up a bio filter that is consuming 4 or higher PPM ammonia. What will happen is when you add fish you will have a massive bio filter die off. The bacteria have to keep in step with the food supply. Adding a few discus to the aquarium will not give you a bio load that requires a nitrifying bacteria colony capable of handling 4 ppm ammonia . If, however, you plan to add hundreds of feeder goldfish into a 55 gallon aquarium, then by all means carry on.
The fishless cycle can start with 1 PPM ammonia. Problems occur when the ammonia goes down, and nitrites climb, and too much ammonia is added which can harm the bacteria and stall the process. Because the filter bacteria multiply very quickly, if ammonia levels do elevate later, the bacteria will catch up. This is far preferred to creating an atomic super charged bio bed that will have a massive die off once feeding is stopped and fish are added. Trust me, this is not what you want to accomplish.
Fill the aquarium with water and adjust the ph and get the temperature correct. Do not use a water conditioner for chloramines which treats ammonia. This is crucial. You can use a product like Dechlor that ONLY removes chlorine, or you can run the tank with the filter and an air stone for two or three days to blow off the chlorine (it is a gas). If you have another aquarium you can add a small amount of water from it, from a thimble full to a cup, to the new aquarium. Adding a product called Cycle will not speed up the process. Using Stress Coat is not recommended as it will coat the bio media and hamper the bio filter bacteria. Stores push those products heavily. I have cycled tanks without adding any tank water. If you build it they will come. A lone piece of gravel from a healthy aquarium can be placed into the tank also. One piece is enough. There is very, very little chance of introducing harmful critters with a piece of gravel, as they live on or in the fish.
In a nutshell, add ammonia, cleaning unscented type is fine, until a level of 1 PPM is attained. Monitor closely and when that level drops, after several days, check nitrites. When they start rising, begin feeding the filter lightly with ammonia. This is where the problem occurs due to misunderstanding. DO NOT go back to 1 PPM of ammonia. This set of bacteria is cultured, so just feed them lightly with a few drops of ammonia daily. Otherwise, you will build up nitrites too fast, which could hurt the bacteria that consume ammonia. Too much ammonia can harm the nitrifying bacteria that consume nitrites, and conversely, too much nitrite can harm the bacteria that consume the ammonia. SO, feed the ammonia very lightly with a few drops, just enough to detect on the test. Then let it completely drop to zero before feeding again. WHEN the nitrites are zero, the filter is cultured. At that point elevated levels of nitrates will be present. That indicates a fully functioning bio filter. This filter can be maintained indefinitely by just lightly feeding with ammonia. A water change or two should be done just before fish are added to reduce the elevated nitrate levels. ALWAYS add fish when the ammonia level is zero AND nitrite levels are zero. Once fish are added they provide the ammonia and no more should be added. You should not see extremely high nitrate levels unless you are adding plant fertilizers or vitamins to the water for the fish, BOTH of which are unnecessary.
After the fish are in the tank and it is time for a water change, I recommend you use one of the following products: Prime, Amquel or Tetra's Aqua Safe to neutralize chloramines from the tap water. These products have an additional benefit. In the event you encounter deadly high levels of ammonia in your aquarium, they can be added to the tank to neutralize the ammonia. These are the water conditioning products I have never heard of going sour in the bottle. Use them with confidence.

The new test strips are a boom to manufacturers who are no longer faced with shipping a liquid product, no longer use glass vials and are extremely light weight. Some of them claim to perform many tests all at once. Trust me, you will get accurate results by using the LIQUID drop type test kits. I have assisted many hobbyists with water issues resulting from acting on readings taken with test strips. When retested with liquid drop type test kits, the difference was enormous.