Meant to add that after the nitrAte rise there would be a good sized pwc
and then you have the cycled tank.
Watching the parameters after you get done adding any other fish you are planning for will be about a month usually for the time when shrimp will be ready after about 4 weeks of no fish losses, spiking parameters and everything just humming along. Then you will have the early stages of a maturing tank.
Doing things like changing filter pads and causing a mini cycle or the tank to recycle, changing substrate will be problematic for a cycled tank.
As you may already know, the filter media is where the BB grow and colonize and you want to keep as many as possible. But they feed on what is available, and starve out let's say if you took out all the fish and didn't feed the tank anything making ammonia.
So keeping things nice and smooth, pwc
each week or when necessary, not over feeding, cleaning but not over cleaning. Giving shrimp the biofilm on side and back glass and wood and plants keep the world happy.