I got a new tank a month ago, set it up, with live plants. The ammonia spiked up to about 6.0ppm, and then gradually dropped over the next 2 weeks. However for the last two weeks it's been STUCK at 0.50ppm. I've been doing water changes of about 25% every couple days to no avail. Any ideas? I'm starting to think maybe 0.50 isn't so bad and just starting to stock it, I'm getting anxious here. I don't want to hurt the fish, but I figure if it's at 0.50ppm and stuck maybe that's where it's supposed to be?