Since the nitrite and nitrate is showing, I don't think you need to worry about ammonia anymore
At most, you could try buying some liquid bio-filter booster, also called beneficial bacteria in a bottle
There are lots of different brands out there, and it's a really good thing to have in stock, just in case
I use one called "fluid filter media" made by EasyLife, I definitely recommend it since it made cycling my tank that much easier
Even if it's cycled it may be good to add some of it now and then. You don't need to add any other water conditioner when using this one!