Outside inside aquatics is without doubt the best aquatics retailer in Scotland, it's a family business and they are the most friendly helpful people you could ever hope to meet. Nowadays they have a good range of shrimp and several different kinds of moss and liverwort that you wont get anywhere else north of the border, all their fish and plants are of excellent quality and in all the time i have been visiting them since before they moved to Haddington, not once have i ever seen a sickly looking or dead fish / plant in their tanks.
Unfortunately the same can't be said for the aquatic center / aquacadabra 2 in Edinburgh, no offense to the guy who worked there but if you want anything other than dry goods this place is truly dire, the fat guy he mentioned is a seriously high grade moron and in my experience they will tell you anything in order to 'make the sale' in there, sick animals abound and whenever i have been in they haven't even known what kind of plants they are selling or the correct identification of half their animal stock let alone appropriate care for each species. they are extremely irresponsible.
Seriously though, no dis-respect to the guy who worked there, i have seen one or two staff who know their blahblahblahblah from their elbow but they're a minority. This place is essentially an extended version of the fish section in 'pets at home', the devils own pet shop.
Basically if you life in East/Midlothian and need to get some supplies/fish/shrimp/plants, just hit the gas when you get to the aquatic center and keep on going to Haddington.