Start with where the white clouds came from
Ask the fish shop where their white cloud mountain minnows came from before you look at price or colour. White clouds are widely bred, and locally bred fish that have grown up in water similar to yours usually settle far faster than fish that have just endured long shipping. A shop that knows its supplier and can tell you how long this batch has been on site is giving you useful information, not sales talk.
Follow up by asking how long you should wait if the fish arrived very recently. New arrivals that are still recovering from transport are a risky first purchase. Waiting until a batch has been feeding calmly in store for a while costs you nothing and removes one of the commonest causes of losses in the first week at home.
Ask about the water the fish are living in now
Ask what temperature the white clouds are being kept at in the shop, and test your assumptions about heaters. White clouds prefer cool water, yet some shops hold them in warm tropical systems, which stresses them and shortens their lives. Fish moving from a warm shop tank into a cool home tank need a slower, more careful acclimation than fish already living at room temperature.
Ask about the shop's water hardness and pH as well, and compare it with your own tap water. White clouds are forgiving fish, but a large gap between shop water and home water explains many mysterious first-day losses. If the gap is big, plan a longer drip acclimation on arrival rather than a quick float and release.
Ask about health, feeding, and the tank in front of you
Stand at the white cloud tank and ask what the fish are eating and when they were last fed, then watch them eat if you can. A healthy school hovers and darts together, fins open, colours clear, with no fish hanging alone at the surface or hiding behind the filter. Ask directly whether that tank has been treated for anything recently, and look for clamped fins, white spots, or rapid breathing.
Ask whether the shop quarantines new stock before sale. Shops vary widely here, and the answer tells you how much quarantine work falls on you at home. If the shop does not quarantine, assume your new white clouds need close observation in their first weeks and avoid adding them straight alongside other fish you already value.
Ask about school size and long-term fit
Ask how many white clouds the shop recommends as a starting school for your tank size, and be wary of an answer of one or two. These are social fish that show their best colour and behaviour in a proper group, and a too-small group hides, fades, and stresses. A trustworthy shop will steer you toward a group your tank can genuinely support.
Also ask what tankmates and temperatures the shop would avoid with white clouds. Warm-water companions and boisterous fin-nippers are poor matches, and hearing that from the seller confirms they understand the species. Finally, ask about their policy if fish die shortly after purchase, and keep the receipt and your water test results, because good shops ask for both. Keeping that purchase and health history with the fish matters later, and KinsLe Transferrable Profiles means a white cloud school's profile can transfer to a new owner with its history, records, and routines intact.