I started cycling a small, 5.5g aquarium back in May or June of this year, with the intention of making it an experimental planted tank. After 3 or more months, it STILL was not cycled, and I was barely getting any register of nitrates; I think the amount of nitrates even lowered at one point. Cycling this aquarium was really not working out for me for some reason, so out of frustration I stopped testing it since I didn't have livestock in it. I've since put plants in it, and I have some bladder snails roaming around, as well. I also just added a mystery snail today, too.
I tested my water parameters--ammonia is still present at around 0.25ppm, my nitrites are 0ppm, and my nitrates are around 5ppm. Is this because I haven't added ammonia to the aquarium, so nitrates haven't had a chance to form? But.. I still have ammonia present in my aquarium, too, even if it's in small amounts. This is even after a large water change; a few days ago (Sunday) I replaced almost all the water in the tank when doing maintenance (I had also added a clay gravel on top of my planted substrate, to keep the dirt from floating around in the tank).
Again, this aquarium has been running for nearly half a year now. It has a filter, light, heater, planted tank substrate, plants (for at least the past 2 months) and I have occasionally used water from my cycled aquarium. Why is it not cycling? How can I fix this?
Is it unsafe to add my betta fish to this tank? He is in a cycled and healthy aquarium at the moment, but I would like to eventually move him to this planted tank. I added the mystery snail to it because I figured it would help with adding nitrates to the water over time. Should I wait until the ammonia level is registering at 0?