Where you gonna get your fish from then gilli?
Are you implying no shops give good advice and therefore gilli wont be able to buy from any shops? I know of 2 in Sheffield I would happily buy fish from as they balance the need for correct information with making money well. They're not as thorough as I wish they were, but if people get sent home with fish for their new tank, they also get sent home with a bag of filter mulm.
There are however plenty I wont go to.
Tbh I don't think you were out of line Gilli, if this has been a thread about a furry (cat, dog, rabbit etc) then I feel opinions would've been very different. I understand what it's like for pets at home workers, but in every store with an aquatics department there is an 'aquatics manager' and people are hired to the 'aquatics department'. They're not all just general store workers. They also have to read quite a bit of material that has been given to them by 'leading vets'. I've had a close family memeber who went for a job in the aquatics department and there was someone on here who got a job at pets at home and told us all how mis informed staff were.
At the end of the day, whether they know better or not (which they don't), the only way they will know better is if you tell them. And you DID stop that lady from going home that day and ending up with dead fish.
The employee will get over it, and may think twice about whether the advice he's giving out is correct.
Yes they need to 'toe the company line' infront of the manager and such. But many managers are still real people, and most are approachable. I reckon most people would care enough if they were told correct advice, and once you've 'converted' the manager then it's likely the staff's knowledge will be updated.
Edit: Also they used to keep bunnies and guinea pigs together at pets at home. Something which has proven to be fatal for plenty of guinea pigs. People campaigned and campaigned and eventually pets at home updated their practices and put a dividing fence in the encolsures. The same could easily happen for fish, but not if people don't ever say anything.