It sounds like it may have been ich.
This isn't the end of the world. Ich lives in almost every body of water. It's only a problem when it overwhelms fish, which usually can only happen when the fish is stressed.
Now, the dojos may be stressed because of the move (even though they prefer lower temps, the switch from the warmer pet store water to your cooler water will be a temporary stressor), so definitely keep an eye on them and, as aquarist said, watch to see if they (or any of your other fish) get any other white dots.
You may want to check your water parameters, and if anything's out of line (
ammonia or
nitrite over zero, or
nitrate over 10-20) do a
water change with a fairly thorough gravel-vac (not deep, just thorough, and be careful not to hit any submerged dojos).