Ready to begin flushing…. I think? How much water should I give? Water only from the top or bottom as well?

Agree that "final flushing" needs to be re named. its about flushing out the build up nutes, thats true, but there are a few ways to do it. You can flush 2 x the volume of pot worth of water thru the soil and then let plant go for 5-7 days and chop. OR two weeks before harvest just use plain water and let the plant use up what it has left. The funny thing about nutes is if the amounts are all out of balance, like when u stop adding nutes and just use water, once the balance is really out of wack, the plant cant uptake anymore nutes even thou there are still some left in the soil, for example without Mag a plant cant use Nitrogen effectively ect. So the two weeks with no nutes ends up causing a type of lock out and the plant flushes itself. Thats how I do it, just added last low dose of P-K booster a few days ago, and now its about two weeks to harvest. I wont add anymore nutes before then. And the last dose of PK booster is to help lock out nitrogen and reduce amount of green in the leaves and buds. I want light green buds not dark green. Light green buds taste better.

Flushing plants is about removing nutrient salts from the plants cells, it is not an exercise in drowning the bejeezus out of your pots, that is only done in extreme cases of toxicity due to over feeding or other such eff ups. Just give plain water in normal amounts, at normal intervals, for 7-10 days and this is all that is needed. Drowning your plants causes hyper moist buds that are then prone to rotting during the drying process. There is no need to wait until anything turns brown, especially your buds, for if they turn brown, they are dead and no good to smoke. Just harvest after the 7-10 day flush and everything should be just fine. Flushing should really be re-named "nutrient with holding period" as this is exactly what it is all about, getting nutrient salts out of the plants cells and not an exercise in imitating a toilet and drowning the bejezus out of your pots/soil. Hope this helps, Organoman.

Recommended amount to flush all nutrition out of substrate is 3x's the potter size in water. 3 gallon potter is 9 gallons water.