Molly Fish Dying!

[richie83]

I've recently bought some new fish to top up my aquarium. There were previously 1 x white Molly, 1 x Male Gully and 2 x Cardinal Tetras, and I introduced 3 new Molly fish along with a loach and 3 platy fish. All the new Mollys have now died and I'm not sure why. There was no visible evidence of whitespot or any other disease I can find on the internet. I'm a little confused as to why they've died - any suggestions?!

Thanks

 

[WILDER]

Size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.

What was the ph of the store to your tank.
How long did you climatise the new fish for.