No way of knowing if you are "cycled". It looks like you have enough cycle alongside the plants to support the current bioload, but there is no way of knowing if you are cycled and can fully stock.
If you are consistently seeing 0ppm ammonia and nitrite then you can safely add some more fish, like an additional 25 to 30% bioload. Keep on with daily testing, manage water parameters with water changes if you see ammonia and/or nitrite. Again if you are consistently seeing 0ppm ammonia and nitrite add another 25 to 30% bioload. Rinse and repeat until fully stocked.
A few reasons why you might not be seeing nitrate.
- You are doing the nitrate test incorrectly. This is very common with API liquid test. Shake the heck out of bottle #2.
- You arent cycled, but due to low bioload and plants the ammonia and nitrite isnt getting to readable levels and nothing is processing to nitrate.
- You are cycled, but due to low bioload and plants the nitrate isnt getting to readable levels.