I agree with Shawn, Arvin. Your growing condition is too humid and the air too still. The spatulata plants are not going to do better as they grow larger if the mould is left on them.
Remember that our humidity in SE Asia is high year round. What temperate growers see as high humidity is anything >50%RH. Our high humidity is when its rains all day.
Best conditions for tropical sundews like D. spatulata would be outdoors and protected from heavy rain via the use of light shade cloth or under partial shelter. Put it simply, bake them under the tropical sun.
