That is a very beautiful aquarium, nice work.
And welcome to Tropical Fish Keeping forum. Glad you found us.
I agree with others that you may be OK with the store water issue, but this is not something to repeat, regardless of how "clean" the store water/tanks may appear to be--SinCrisis, take note please.
All water containing live fish will have "stuff" in the water from the fish. And most likely there will be things you don't want if it can be avoided. Excess ammonia (and from the fish in the bag), waste, pathogens, bacteria (the bad sort), parasites...while some of these can come on the fish itself, adding the water will significantly increase the probability of introducing something detrimental. It's like not quarantining new fish--many times we can get away with it, but not always. Best not to take chances in the future; always net the fish from the bag into the tank after the temp is equal and you have mixed some of the water (adding the tank water to the bag slowly). Not everyone does this latter point, but many of us do.