We have made it through 12 months with our only loss being poor Mr Lazy who didn’t make the first month and I suspect he didn’t make it more because of the conditions before we bought him than after. (no heater on tank at store in middle of winter, next week the ones that were left were down to only a few legs each)
We had actually thought that we had lost Voldemort as he hadnt been seen for a very long time. I was collecting them and putting them in the isolation tank as they came up from below ground ready to empty the tank out and redo it and just as I was thinking Id go digging for the body and clean it on the weekend who should pop up but the last crab. I suspect that half the time he was coming up but just being identified as Fili
So YAY!! Guess we must be doing something right
and thanks for the great information here, I doubt they would have all made it if Id relied on the pet shop 
