I know I have read forum after forum looking for info on how long it would take for my tank to cycle with fish. And the answer is always something along the lines of "every tank is different, get some safe start." I stubbornly didn't want to pay for safe start if this thing would cycle naturally. So in my case, here's how it's going. 20 gallon tank, 3 little fishies, some free snails, and a live plant. One week in got ich, had to remove filter to treat, so set my cycle back to fresh. Weeks 2-4, not much happened. Manageable ammonia roughly .25 to .5, water changes every couple days. Week 5, went out of town and left tank in care of college neighbor kid. Also, started using Prime since I wouldn't be around to change water. He sure as heck fed them, I assume he dosed the Prime correctly as the fish lived and the tank was a wreck. Week 6, came home to nasty tank with all sorts of food floating in it, extremely cloudy water, and brown algae everywhere. Thought my plant was dying. Removed it to more sunlight for a couple days, gave it a hydrogen peroxide bath, rinsed and returned to tank. Ammonia was out of control. Changing water daily and sincerely questioning if the new use of Prime was some bad advice. Beginning of Week 7, woke up and plant suddenly looked fabulous, lush green color coming back and pushing out loads of new growth. Plant must be enjoying this ridiculous ammonia. The water is clearer too. I think the brown algae has almost run its course. Test the waters, heck I'll check Nitrite too (I hadn't been checking it since ammonia wasn't dropping). Wow! Something's happening! There's actually Nitrites! Barely but definitely there! I didn't change the water immediately as it was light, so I dosed Prime and checked next day. Nitrites much higher! I couldn't get a good read on the color. The lighting is funny in my house at sunset and I couldn't tell if it was showing the 2nd or the 4th level of purple. Did a 50% water change since I couldnt tell the intensity and will now be on the lookout for Nitrates. I've read some accounts saying it takes twice as long to see Nitrates as it does to get Nitrites, and I've read other that say the Nitrites happened so fast they missed it. I'm hoping mine is of the faster timeline! Oh, and fishies remain happy and healthy so far!