Blue Mammoth

Ok So as you know I have the 3 plants in 1 tent and one rescue test plant in the cupboard space as 4 at this size in the small tent was to much and the other plant had been attacked by my silencer... Anyway the 3 plants have obviously been flowering for sometime now as well into week 10. The 3 are all growing at different rates not 2 far apart but about a week each which is just plants doing their own thing. I have removed a decent amount of leaves on the 4 before beginning the flush for 5 days minimum or until ready to harvest but have to check when. Question - this is my 1st time but researching a lot and trying to find out when to know when they are exactly ready to chop. (I have a gardening background) My idea is now I'm starting to flush the one that is most ready as this could take 1 to 2 weeks and then put the experiment one back in the tent once the other one is drying in the box. Once this is done I'm going to use canna boost on 2 and start to flush the next most ready one. I have built a box, I use the term built lightly hahaha. ( put together ) I also used small pieces of cardboard to space out the stalks i.e. cut pieces to size with a groove just to space and bring the buds out to catch more light. Cardboard is soft and the plants have accepted this process no problem just be gentle... (4 days ago) When I cut the leaves that shade the buds. (don't be shy with that) The main 1st plant is totally covered in THC like nearly every single bud including underneath nugs. The others aren't far behind. It is literally like they are all 1 week apart in growth. Canna coco a + b - feed Canna coco pro em... coco soil Canna boost will be used on 2 to see results😬 24hr lighting 1st - 300 watt LED - 6 weeks 2nd - 300 watt LED and 250 watt CFL - 2 weeks 3rd - 400 watt HPS Used soft water, left for a minimum of 24hrs at the room temperature of the plant to let any chlorine evaporate and the Canna to mix properly. Will be testing Canna boost soon as well. Window in room left open about 2 - 3 inches- out side temp - averaging 10 - 18 degrees Celsius which allows the fresh air to blow in gently. Tent left slightly open always 1/4 sometimes a little more dependent on the outside temp of air coming in to the room that the tents in, which has nothing much in it and size is around 15ft - 8ft. Tent is about 2m by 1m squared and about 8ft height. small fan points to opening which allows air to circulate and is faced the opposite way when tent is open in the mornings to dry up any condensation. ( Open tent fully for 2 hrs every morning which allows for any moisture build up on side of tent to evaporate. ) Not used my air filter so far only because the humidity is minimal with this method and there is plenty of air circulating constant but I do keep an eye on it. Its a very small set up making it easy enough so far to manage and learn from... Any and all advice or ideas are welcomed. Thanks for reading.