Harvesting top buds

Hi everyone, I have a plant with well developed top buds but less developed lower buds and I was gonna harvest the tops and keep the lower ones going because I've read a lot of people do that. My question is should I flush my plant, harvest the big nugs, and then add nutrients again? Would the other buds be okay or would the flushing kill off the plant? I just know you should flush to get them nutrients and stuff out. =P

Here, I'll be the first one to say it:

I flush my toilet not my plants.

Argue away.

Taking the big tops is fine and a common practice. You can cut back on nutes towards the end but the plant still needs some nutrients.

No need to flush your plant.