Thanks for the comments.. so I discussed the issue with my fish guy from my favourie lfs and we basically worked out that this was all my fault!! 2 days ago I did my usual weekly %50 water change.... however I forgot we had a cold snap here and the tap Water going into the tank, instead of being 10-12 degrees (it meant the tank water only dropped a few degrees) was closer to 4-5 degrees! So the tank water dropped closer to 15 degrees... arghh! So basically the pike figured it was spring breeding season and decided to clear the tank to spawn... what a F up! It's tough enough to lose 2 of your 3 favourite fish... but it's another to realise you directly caused it.. there is a very rude word beginning with a C that I feel like now...