Help dialing in?

Hello everybody!

I'm looking for help for my 2nd round of shrimp keeping.

3 months ago, I was gifted a 10 gallon aquarium with a small population of shrimp. The tank was somewhat abandoned and I did my best to try and rebuild it. I rebuilt it and successfully cycled the tank, and even added some chili rasbora and celestial pearl danio (6 of each).

During the initial rebuild, I added a slew of new plants. Anibuas petite, Java Ferns, and Floating Salvinia Minima. All of these plants are happy and have been growing well.

After the rebuild, it seems that one by one, from an initial population of 15, the shrimp began to die.

As of this weekend, I bought 10 additional cherry shrimp with hopes of starting a colony. Today I woke up to one dead shrimp and I observed one shrimp "jumping" but remaining stiff between jumps, until it stopped moving all together.

My tank parameters are as follow (measured with API Master Test Kit:

PH: 7.4 - 7.8 Ammonia: 0 - 0.25 ppm Nitrites: 0 ppm Nitrate: 5.0 ppm GH: 9 drops (~ 160ish ppm?) KH: 6 drops (~ 100ish ppm?)

Can anybody offer up any ideas or help?

I would love for this to become a booming colony!!