but surely if you are adding ammonia on a regular basis and your test show that there is no ammonia or nitrite you would know that the process is working. the only reason you would want the nitrates there would be as additional evidence. but the results of the ammonia and nitrite test would tell you when the cycle was complete. i'm not saying the sponges are necessary or that i would consider buying them, merely that i don't think it would cause problems to use it.
edit- sorry missed the replies in between
do you not need to check that the nitrites are being converted to nitrates. it is possible, and can happen in cycling, that the tank will have nitrites, but the process of breaking them down has not started. if you relay totally on a nitrite reading, it is very possible that your tank will not be cycled. only when the nitrites are being converted to nitrates, would the cycle be complete.
it is quite correct that you would have nitrites in the tank if the process of breaking them down has not started, this is my point.
when the bacteria 1 has built up a big enough colony that there is no ammonia showing on your test you will get a nitrite spike because the bacteria 2 has not yet built up enough to cope with the large amounts of nitrite being produced by bacteria 1.
SO if you are showing no ammonia and more than 0.25 of nitrites then your cycle is not complete. when you are getting clear readings on ammonia AND nitrite then the cycle should be complete.
because if the ammonia is being processed quickly you will either have to process the nitrite quickly or you will get a build up, these are the only options available.
if you are processing the nitrite quickly there is no problem, your filter is handling your bio-load successfully and so your cycle is over.
if you get a build up, your test reading will show high levels of nitrite and you will know your cycle is not complete.
when you get to zero ammonia and zero nitrite within 12 hours of adding the ammonia, you are good to go.
