Not what you wanted to hear I'm sure but
SOUND ADVICE from the respected 'OldMan'
I was under the impression that you had bought a second hand tank from ebay or the like and was told it was cycled in which case without fish or an ammonia sorce it would become un-cycled very quickly.
If, as I now suspect, you have got a new tank, filled it with water (and whatever else the LFS managed to get you to buy) and just waited a few days, it most certainly isn't cycled and is not ready for fish!
As the 'OldMan' suggested, read up and follow the 'fishless cycle' program. It will be the best thing you could do if you wish to become a successful newcomer to fishkeeping. It will also earn you respect on these forums.
Just so all things are equal I will tell you there is a method of cycling WITH fish but to my mind it sounds like more work. It will more than likely result in dead fish, frustration and eventually yet another second-hand tank put on eBay by a failed fishkeeper
FishLESS cycle, it just makes sense!
