[JustOneMore20]

I wouldn't try to adjust the hardness. Your pH is good, even if your water is hard. Most fish tend to adapt and screwing with the hardness/pH can cause issues sometimes.

Neons are a weak fish these days, probably from inbreeding and over breeding of them.

I bet you are getting a mini-cycle from taking out the rocks. It doesn't look like you have alot of ammonia, but I would continue to check it for the next week (and nitrItes too) just to be sure.

If hardness were the issue I would think that they would have died soon after being introduced to the tank, but I'm not certain.