[ravensgate]

All shrimp will turn either pink or white when they die, it's how they look when alive that tells you if bacterial infection is suspect. Infection is internal, milky white cast to the exoskeleton says molting will be soon. ON their back and twitching sounds like a toxin of sorts, if that flit around then sink, twitching that could signify a bad molt. The charcoal bamboo, did you boil it before using it? And the leaves, you said microwaved, do you mean in boiling water? PArams sound ok, any idea on pH?

Are your water changes done quickly, slowly, spot on on params? A drop in GH, TDS or temp and too quick of a water change can force premature molting and kill them. If it's toxins I would do a large water change and get some purigen on the tank if you don't have it.

 

[ravensgate]

What are the params of the water you are using for a water change? Are they the same as your tank? Is it tap water? Tap water changes, often seasonally. Are you topping off with RO water or tap? This will add minerals and hardness if you are using tap. Neos are hardy but they are not bullet proof, as you are now seeing.