I've been following along, after this well beaten horse...
Dan's is one of 3-4 of sellers I buy from, as I don't have a good local, so everything I buy, comes from a shipper... I buy the most from Dans... and while I'm using RO water in my tanks, because my water is as hard as Dans, and I don't want to long term subject my fish to alkaline water... I have a nearly 100% survival rate, on fish from Dans, and pretty much all the sellers I buy from repeatedly, at least for the 1st couple weeks... to receive fish from anyone, I typically pull a cup of water from my tank, then cut the bag open, and pour as much of my tank water into the bag, as I can... my ideal, is a 50% mix... but in the tiny individual bags, that Dans packs in, there may only be room for 10% of my tank water to mix in... I usually give that about 1 minute, then pour the bag through a tank dedicated net, and add the fish directly... I'm actually surprised that I don't lose more going from hard to soft, with that procedure...