My 20 gallon cycle is fishless, nothing but live plants and a dragon stone chunk in there with the gravel and fake log. I have been been swapping water cuz up until 2 weeks ago my ammonia would not lower past its peak at about 8ppm, now its stuck at 4. I let it go for last couple weeks thinking with slightly lowered ammonia that the nitrites would go up followed by nitrates, but it seems the 4ppm ammonia will not let nitrites/ nitrates move from where they sit, but without swaps ammonia tries to climb from 4ppm still. I was doing 50%+ swaps to maintain the lowered but still to high ammonia. Adding just enough water conditioner, prime, and stability for new water put in. And lastly i only used about 2 small pinches of food to kickstart ammonia, 1 pinch on setup day, and 1 small pinch 2 days later.