They look really good but I'm wondering about your nutes and feeding schedule as the buds are smaller than I would expect at 3 weeks into flowering.
I mentioned how I prep for flowering in my long-winded post to Drop that Sound above. I was always experimenting with my grows to keep things interesting after many years of doing it. I went back to school in my 30s for 3 years to get a diploma in environmental chemistry and had hoped to go to uni for at least a bachelor's degree but life got in the way. 2 small boys at home and a very non-supportive spousal unit who left a couple years after I graduated making me a single dad closed that door.
Anyway I used to monitor the ppm drop in my tubs and noticed that when I flipped to flower the rate of drop would increase in the first week up to 4X what they were eating before the flip. Within a week after the stretch stopped they would go back to rates the same as before the flip. That's when I tried feeding one tub more bloom nutes with a half dose of Big Bud, (which I've used since it came out and hate to grow without), a week before flipping to 'prime the pump' so to say. The other tub with the same number and strain of plants got more bloom and BB in the 2nd week as recommended on the containers. The pre-primed tub's buds were lots more plentiful and twice the size as the other one.
As I always used RO water only and had to buy that I didn't change nutes very often. No drain in the garage grow meant hauling used nutes into the house to dump drawing attention to what I had going on too. I would start off the clones at 300ppm using equal amounts of all 3 bottles. 1ml/L of each worked just right for that. For the first few days until roots began to emerge from the net pots I would use a turkey baster or large syringe to suck up some water from the tub and squirt it around the top of the pots to keep the roots wet and fed. I always cut a smaller hole in the lids to get water in or out and would just keep the hole covered with anything to block light. I'd rent a hole saw to cut holes for either the 5" pots or 3.5" ones and had a 2" saw for the access hole. To drain a tub I used a drill pump and could run a hose into the sump once we moved into the place we're at now.
I could never see the sense in changing nutes every week during the early stage of veg. They would hardly use any so once they were starting to grow I'd just use syringes to add more nutes to the tubs to boost the ppm or maintain it at my target ppm. I would start the plants in the shorter tubs that hold 35L at one inch below the bottom of the net pots. A week before the flip I would pre-mix my bloom nutes with BB in a taller tub that holds 50L when full. Then just take the lid off with the plants and drop it on the fresh tub as the lids are the same size. The next change would be after the stretch when I would switch the nutes to a Lucas Formula type of feeding. There is a specific formula to follow but it basically means to not use the Grow and use 1 part Micro to 2 parts Bloom plus the addition of BB until the end of week 5 or later depending on the flowering period of the strain being grown. Most hybrids are about 8 - 10 weeks but I used to grow a lot of sativa dominant strains that could go up to 16 weeks before they were ripe.
During the stretch plants want lots of all the nutrients and higher levels too. Once stretch is over they need less N, P, and Ca but more K, Mg and S. Your standard P/K boosters if used past the stretch period are feeding too much P which is what can give the buds that 'chem' taste when smoked. Big Bud is 0-15-35, 10%S, 20 amino acids plus citric and ascorbic acid, (vit. C) so doesn't add extra N which can retard bud growth later in flower or excess P. I get the powdered version of BB as it has a lot longer shelf life than the liquid.
I was looking at those first pics of your setup and wondering how you get around in there with everything fixed in place. I also noticed that you're not tying the grow tips down to the net which unless you can raise it later will be of little use to keep the colas from falling over so will need a 2nd level of netting like I've seen many other grows resort to. I've done a lot of actual ScroGs and would start training the grow tips by using short pieces of twist tie to hold them to the top of the screen thru veg and continue tying them down during the stretch. As side branches would grow up they got tied down as well. By tying the grow tips to the screen rather than weaving them I could easily remove the 3 or 4 bits of twist tie near the top of each branch and shift the whole branch over if need be to cover the surface evenly. Once the screen was about 75% covered I'd flip and keep tying down during the stretch so by the time that was over the whole screen would be covered.
My tubs weren't all connected like yours and I had them sitting on wheeled dollies so I could sit on a 5gal pail and turn a tub around while I worked on the top. for DWC ScroG I rigged up the tubs like this so the screen could rise as the plants grew. There was rolls of that sheep fencing here when I bought the place so I used it instead of buying screen. The branches would quickly reach the edges so I'd tie along the edge then turn the tip toward the inside to grow it's way across again.
This one was a mother plant growing in a 2L plastic tobacco can full of ProMix HP I made a DIY net pot for from another can to convert it to grow in DWC. I cut the rootball off half way down, put some folded up snow fencing in the bottom of the net pot to keep the rest of the rootball up off teh bottom and top fed it until roots emerged but that only took 4 days.
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This is one of the lids I made using the smaller pots for a SoG type grow. It's sitting on one of the wheeled dollies I made. Not the access hole I mentioned earlier. My air lines go into the tub through small holes drilled just under one of the handles so there are no holes in the tubs below the water line thus no place for leaks.
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I was planning on growing a few plants but should have started months ago. If I got some going now they would be starting to flower just about the same time the hemp field down the road from me would be pumping out clouds of pollen. I had to stop growing autos outside as they got all knocked up which really kills the potency and yield. I know damn well that pollen would get into the grow room too so I'll wait until probably end of Oct - early Nov before starting any plants. I'm hoping to be out in BC for the month of Oct to visit family and get up to the family cabin for our thanksgiving when is the usual shut the cabin down for the winter long weekend trip. This year my b-day is on Thanksgiving day, Oct. 14, so I could get turkey on my birthday! Probably won't have turkey up there tho as mom is too old at 97 this Aug and blind now and won't be going so I'd have to make the turkey myself. I'll have trout instead as they are biting good and nice and fat by then. A lot depends on the wife's health situation too tho. Something is going on that made her lose almost half her weight in 5 months last year and they're still working out what the problem is but think it's her thyroid.