Cycling a fry tank with a used filter?

Ok, so I bought a 2 gallon tank with a heater and filter. It doesn't have a light though..does that matter? Anyway, I put some Stress Coat water conditioner and Stress Zyme pro-bacterial stuff in the water and it has a used filter in it. I got it from craigslist. I have a water test kit and plan to monitor it closely, and not add anything until my Nitrites and Ammonia levels are both 0. I just want to know about how long it will take before I can put the mama platy in it. She's very pregnant, and I expect the babies within the week. Just so no one freaks out, I'm only keeping the mama in there while she's giving birth, then moving her back to my main tank. And also I just want to add that I have already read the fishlore article about the nitrogen cycle.