If they were shocked due to the change would it normally take them a couple days to die?
I've seen that happen a lot while I've been here. That being said... my first fish, not knowing any better, got floated and then dumped into the tank. Luckily they survived. I guess my conditions must have been close enough to the fish stores conditions. All we can really do is take educated guesses and try our best to minimize the impact on the fish as they move from one environment to the next. Maybe they were caught wrong, maybe they were sick to begin with, ammo poisoning... it is really hard to say.
As far as acclimation procedures go, after my first fish that got thrown in (water and all) I read a bit more (
Acclimation Article here on AA ) and then started using the shot glass method. I moved 1 shot glass of water into the bag every 5m, dumped half when it got full, test
SG & pH and do it again as needed until parms match. Now I use the drip acclimation method but I'm not sure I have that perfected either.
I've read that it is really important to raise the temp of the water before opening the bag and not to put an airstone in the bag with the fish due to the fast increase of the pH.
Another Acclimation Article
I think you did right to do a partial water change right away. With high levels of ammo you're going to want to do water changes. It won't prolong your cycle as long as there is some ammo to feed the bacteria. The one thing that is important to remember is that if you're mixing your own
SW then you're going to want to make sure that you have the water mixing for 24-48 hours before adding it to the tank so that the undissolved chemicals in the water don't hurt the fish. Wait 24 hrs and test the
SG, adjust as needed, let mix for another 24.
When your ammo/trite come back down add another fish.
