Help! Ping fungus treatment

I have four species of Mexican <i>Pinguicula</i>: <i>P. moranensis</i>, <i>P. ehlersiae</i>, <i>P. cyclosecta</i>, and <i>P. laueana</i>. The latter two are just coming out of dormancy. My moranensis is a good size at about three inches across, while all the other ones are well under an inch. There is a haze of white fungus just beginning to grow all over the surface of the soil in the entire pot. Should I use a fungicide spray ASAP? If so, should I use Banrot or Cleary 3336? Are there any special instructions I need to follow? Someone please help me as soon as possible. Thanks!

For an interim measure, spray the surface with mineral free water, and decrease the humidity: this often checks the growth of fungus. I think that I would repot the plant(s) before I went and sprayed with chemicals, with which I have no experience or advice.

I recently top-watered the tray, and the fungus is less evident and seems to be not too bad as of yet. I don't see any evidence of it spreading to my plants, so I'll probably hold off on any fungicide until I sense a real danger.