The white spots over the tail are not normal. This is a whitespot or ICH infection (same thing, just different names for different areas of the world). I'd use Waterlife's Protozin here in the UK, but you aren't from the UK so I don't know whats available to you. Any off the shelf Whitespot medication will cure it though. The raised scales could be just because the fish caught itself on an object while flicking or rubbing from an itch caursed by the Whitespot infection (if one fish has it like that, most, if not all, will have it also) or it could be bacterial...
Is it just the odd scale raised, or the whole bodies worth? From above, does the fish look like a pinecone?
ICH is a stress related disease, so something is upsetting the fish. What size are these babies at now? I presume they are all the same type?
I still suspect something might be up with the water. Can you get the LFS to test your water for you when you get the medications? Make shure they use a liquid regent based test kit and write down the numbers for you. Don't accept just "it's OK" or "it's poor" You will however need your own test kit, again liquid regent based not test strip.
Whitespot/ICH is a killer, and once on the gills as it is in your case, it can kill a fish within hours. You need to get some meds for these fish ASAP, or you may pay the price in casualties...
All the best
Rabbut
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