depending on how long you vegged flushing to get rid of any salts is a good idea now some of these noobs probably by the cheapest nutes possible and expect miracles
) but in reality reading instructions and goin by what it says ( Good starting point ) now some experienced growers will have a Ec meter and get indepth on there feedin chart giving there plants maximum nutes
so in veg exceeding 1200 ppm and Flower 1500 +
All nutreints are salt based from what i under stand thus in a long veg period then goin into flower causeing major problems yellowing burning just read all the plant problem threads an do the math i am in 2 weeks flowering leafs are yellow , brown tips, curling, etc
You may run less N in your nutes but quadripple P and K bloom 0 - 53 - 33 a A-B like 1 - 4 - 8 etc
so is it good practice to flush prior to goin into flower its all up to you but i would rather then be chasing your plant to health and stressin the plant when you need it as healthy as possible for yield purpose
Now flushing harvest is also a good idea many growers use chemical nutes this getting rid of any chemicals in your medium this giving your dank weed you so worked hard for a better taste its all up to your selfs peeps if u flush or not good luck