It is not ich it doesnt even resemble ich. She is the only one that has a white spot. Water changes and cleaning are done weekly. Water changes are always done between 25 and 30 percent. Testing was last done a few days ago. ammonia was at .25, nitrate was at 5 nitrite was at 0 and ph was at 8.0 the tank is over 6 months old so it is fully cycled. I have added prime as the ammonia is a bit high. The tank is 50 gallons and has mollies, platies, 2snails, and 1 pleco in it nothing else.Do any other fish in the tank show white spots? The first thing that comes to mind is ich. But that is getting ahead of things. What are your water test results; pH, NH3, NO2, NO3,? What size tank? How often and what % do you change your water? Has anything new been added to the tank? How old is the tank? Give us the whole story so we can do more than "Hmmmm, it might be..."
There are too many references to white spot on fish on the internet. If none of your fish are showing any signs of problems, I would do nothing, keep an eye on it and see what happens. I might be more concerned about the ammonia.
The picture you uploaded is not clear. I uploaded an edited image. Are you talking about 1 or 2 or something else. A suggestion; take a video instead of a still - you can pick the best focused frame.