I grow in active compost with home brewed teas as flowering nears complete i start back off on how much tea I give them per week. Bout week 6 i start to back off. Then a week before i take them I flush the soil with R.o water and molasses. I do a gallon of water per gallon of soil. I flush a gallon at a time wait ten fiffteen minutes and do it again. Wait and do it again. Then I just leave them that last 7 days.
i don't flush at all!
the final 2 weeks the plants pack on the weight so WHY would you want to starve your plants by giving them only water?
in my opinion it's better to gradually weaken the nutrient solution. for example: 2 weeks prior to harvest. fill your res and give it full strength nutes. over the next 2 weeks only add back fresh water to top off your res. in my 20gal rez, in 2 weeks i'll have added back 40 gals of fresh water. by harvest the ppm's of the nutrient solution is very low.
my herb burns great with a nice white ash, i have great resin production and an awesome taste.
giving your plant nothing but water for the last 2 weeks will take away from potency and yield...if u know how to feed your plant the right way...flushing isnt even needed..but i'm sure all of u keeping these nute companies afloat will disagree...just go look at the science of how MJ grows...and someone tell me why u would deprive the plant in its most critical stage of growth.
I give my plants their last feeding 3 or 4 weeks b4 thr dun maybe give thm a bit of molass and sugars. I grow organic in soil and only feed my plants half strength at most. I've never had a problem with potency,taste, or aroma being lost with a longer flush. As far as yield I cud care less, I find the dankest buds tend to cum from smaller plants in genral. Just ask Subcool yo
I flush with clearex 2-3 times during the flowering period, and use a product called drip clean by house and garden the entire grow which reduces salt build up. Then I flush the very last week with plain H2o. I find I get massive growth the second to last week using a product called shooting powder and would hate to lose the week to flushing. My buds burn smooth, smell amazing and taste delicious.