Sadly, I don't have enough room for driftwood in my tank [only a 2.5 gal] and I have never seen those pellets. :(
Could hard water cause their fins to curl? I know his water isn't really wonderful 100% of the time, but I'd have to put about 3-4 products in it to get it pristine... [since I was just told that water in Louisville has ammonia in it and the dechlorinator I use doesn't neutralize ammonia]
you can get regular old peat moss at the garden center at home depot or lowes or any local garden store.. just put a little in the toe of a pantyhose and put it in your filter and it will do the exact same thing as the pellets. Other things that can lower your hardness are IALs (indian almond leaves) but you have to order those offline (they're cheap).. snails absorb some of the minerals but your tank is too small for a snail.
I suggest getting peat moss from the local garden store or ordering some IAL (the IAL will tint your water though)