thanks for all the advice. Is there a good fish forum, like the mumsnet of the fish world?
The shop where we bought the tank from is fab, its an independent shop who seem to see it more as a hobby than a a business, when we were in there a customers was having his fish checked for illness, most were just old and were advised to just put them back and let nature take it cause rather than being flogged some unnecessary medicine and a second man came in with a filter not working, the guy said oh it probably just needs a good clean, took it apart cleaned it and handed back again resulting in no sale! They have said bring a water sample in and they will check it ect.
DH wants a marine tank next but were starting at the beginning with the tropical, having moved on from goldfish/black mores!