I would check it again. If you come up with the same numbers, you may have some faulty kits. But I bet thing will have straightened up a bit since your last initial post. If not, do a large water change.
How is the livestock doing? You are getting a mini "cycle". If you livestock looks fine I would give it a da or so. If the live stock is not doing ok I would do a large water change.
If want really wise words, and this is what I generally go by. Don't buy used unless it's a running system. Even a running system can have its complications though.