Good move Mand! No doubt they should have a few days to adjust to their new 'surroundings' before you decided to 'bin them'. Although if done right transplanting causes very little if any slow down.

Ya know you can buy very inexpensive pH testing supplies at pet stores. They aren't super accurate, but it would at least give you an idea of what your water pH is. But if you've never had problems in the past with something like this, it probably isn't the water. My guess would be the compost, as I suggested a while back. Hey maybe your wacky neighbor was peein' in it!!!

Hopefully you can learn from this and if it ever rears it's head again will know the proper steps to take. It for sure isn't normal.

Have a good one Mand! Sorry you're having problems...again.

Marc