Flush questions

Hey I'm getting pretty close to harvest time for my platinum og kush. I have about 21 days left according to the 8 week flower time for this strain. We plan on using the botanicare clearex to flush.

Our plants are in 5 gallon buckets with FFOF soil.

My question is should I start the flushing process next Saturday which will be about 15 days left? I've read different things about times to start flushing.

Also how do I use the clearex my feeding schedule calls for 10ml but is that per plant or do I spread that between all 6 plants?

How many gallons of water should I use to flush each plant in the 5 gallon buckets I've read 4x the gallon pots your using? Which would be 20 gallons of water for each plant?

One last question what is the ppm I should be looking for to know when it has been flushed and how many times should I flush before harvest?

Thank you for any help this is our 1st grow and we want to finish it off correctly!

I wouldn't go too insane with the flush requirements that the manufacturers of the product profess is needed, especially in soil. First off, forget what the seed packet say's as far as due date. You will always be off about harvest time. In soil, the best way to clean your plant is to drop off all nutes by 75% for what is expected to be the last 3 weeks. To flush 5 gal containers would be a nightmare. Hydro is another matter as far as flushing is concerned, so just use a weak nute solution for the last couple of weeks and that will be fine. Peace

plants are looking great, but imo, they look like they've probably got closer to a month or so left on them easily.. no big deal as i've found that most breeders usually give the shortest flowering times for their plants, and i've found they're usually off about 2 weeks if not more..
as far as flushing, i'm a believer in that flushing does nothing for the taste of the buds, or the way that they smoke.. i just cut back on nutes like jim above me said the last two weeks or so of flowering..
being that you have more than one plant, i'd suggest doing the following so you can judge for yourself if you think flushing does anything for the plants.. take half of them, and flush them how ever you want.. and the rest of them, don't flush them, simply cut back on the nutes the last two weeks.. when they're done, dry and cure them the same exact way.. after about 3 weeks in jars, pull a bud out of each jar, the flushed and unflushed.. get some friends together and do a taste test.. don't tell them anything about either of them being flushed, and not flushed.. just tell them something like it's two different phenos of the same plant or w/e you want to tell them.. smoke and compare the two. it's pretty much the only way to get a fair test and find out for yourself if you notice any difference.. i have done this myself, and didn't notice a bit of difference, and have since stopped flushing my plants..

Thanks for the help!