Drain or no? some advice

A question from a fellow grower:

i have a question….I am growing with ebb and flow…in a tent…right now…i
am using the aggressive vegetative grow food…and soon I am going to
bloom them…my dilemma is…do I need to drain all the water out of the
reservoir and start with new water and the bloom food…or do I just start
adding the bloom food…

It may depend on the type of nutrient regimen you are using and the recommendations from the manufacturer as to whether or not you need to do a complete reservoir change at that time. But generally, and depending again on the technique and other factors like the size of your reservoir or the number of plants attached to it, most people do a complete reservoir change ever week or so and certainly during major changes around the transition from veg to flower.