Diddlebug ... Frapadoodle is joking ... you'll get used to him eventually lol. He's jealous of my panda cories cos he wants some and can't get any in his area so he's always telling me to quit bragging. He's just kidding - just his sense of humour
@Lilliefishy - 15 years? wow!! There was me thinking my peppered lot were getting old and watching for signs of old age and death. I can quit that now. It would be lovely to have them with me a while longer... especially my high fin male
As for the deaths Diddlebug, it could be that the filter was too strong, it could have been the shock of being moved, I doubt the young mollies would kill them but you never know with adding new fish. Some fish get territorial and any new comers arn't accepted well.
Now, this is the important bit. Keep an eye on your water stats if you've switched off your filters as I doubt that sponge filter will be cycled. Are you able to keep the sponge running
and run one the others that is cycled? You might be able to limit the flow if it's too strong ... are you able to turn it down or is the flow fixed? I have limited flow on a filter outlet by tying a pair of tights (or panty hose as you call them) around the outlet nozzle. I've heard of others limiting it by putting some fine filter wool over the end too. It's not good for the filter in the long term but on a short term basis it should be okay provided you don't over-do it.
Please check your water daily now for ammonia and nitrite and be ready to change some water if you see readings over zero. Cories are often sensitive to poor water conditions. I lost 2 panda cories to a very small ammonia spike after I over cleaned my filter and so I know some species of cory really can't handle it
I plan on getting a few more pygmys for the group tomorrow. 
