Better explanation. I use up to the day before. Noticed no aftertaste. I cure a minimum of 2 weeks. I don't ever flush any more.

In my humble, unproven opinion, I believe it is N that causes that aftertaste, and I never give it any more, I just repot on a time schedule. I give minimal nutrients, and usually the only thing I give late is molasses and Ultra

I actually wonder tho, just how much effect the Ultra has over UVb for the last 2 weeks and some other things. I do not like the way stuff will grow in the bottle, that is for sure. Molasses seems to do just as well.

I also have no experience with autoflower, as I prefer a perpetual garden.