4 weeks into flowering, some issues...

I am 4 weeks into flowering and i dunno what some of my plants want already. I flushed them for the second time last week and fed them 3 days ago as they needed. I kno some of the dots on the fan leaves are calcium def but i am not sure if its mites as well. I check under the leaves with a loop and see no mites, plus i have 2 pest strips in the room. What do my plants look like they need?
Could it be because i am in miracle grow soil that when i flush its still releasing its own nutes ?