Need help: 5th week flowering, what do you think?

Hey guys,

first time grower looking for some advice.
Been growing 4 plants indoor using 400 watt HPS lamp in a 2m x 1m amateur made grow closet.
No idea on strain of plants except that they should all be the same.

Growing in regular gardening soil.
Been using Hesi TNT complex during growth and Bloom complex + Phosphor Plus since flowering.

The plants have just finished their 5th week of flowering they're about 1m20 tall.
1 seems more mature than the others (50% of pistils are amber whereas others are still pretty milky white).
Looking to harvest latest in 2/3 weeks.

Haven't had a look up close at the trichomes yet (still looking for a good microscope, not the easiest thing to find here) but I'd appreciate any guesses on when they should be ready to harvest because I think I should start flushing out the nuts.

Also, planning on doing a 36 hour of darkness prior to harvest for max resin output. Any thoughts?

Thanks!

Looks geat for a first grow. Macroscopically a good educated guess would be two-three weeks. There is no scientific evidence to support that a 36 - 72 hour period of darkness prior to harvest ensures more resin formation.