Look good.. I would say pH 5.6Flower andd would say on the last 14days flush with pure water only!!! Its ok let your plants fall apart by cannabalism! I fist liked the Idea of pH at 5.8 but I keeped seeing better results lower I went. Dont go lower then 5.4! I would Also think about running H202 in your system, becuase it will clean out any bacteria/root/alga, anything that isn't pure lol.. It' also release it's extra 02 molocule and addeds oxygen into your system.. Replace every second days with h202.. It can be expensive becuase it is hard to manufacuter! BTW do not let touch hands, i did and fuck it burned when I layed my weight on my hand after catching myself from falling over when watering!!!! When i streched my hand i really noticed the bleaching in my hand and it burned! So be carefull!
I dont use your line of product and I try to keep it mostly simple! I use a product thats made here in B.C Canada, 3part and it works WELL! I also use it's Gurrilla bud flower booster!. If I have troubles or anysigns stop with your nuturents and use epson salts for a couple days then go back on your nuturents! this is very vag info, Keep doing what your doing, but fine tune your system!! maye go little smaller pots and increase air intake, and maybe run the same PPM you wre running at but drop pH a little to watch the response!! Or try using double bucket system.. Thats what im focusing on. GOnna get it 100%right soon lol.... I use a 30Gallon Res with 5Gallon fresh ph Adjusted water for my auto top up, 24inch worth of air and then I used my double bucket system with 6inch net baskets and hydroton. I top feed 2lines in, (put them on timmers-15mins on and 1hour off-24/7) Then run your buckets 1/3deep and make sure u have termendous amounts of air in, and NO light, make sure NO light can get in!!!!!!!!!
Run low PPM around 600 adn pH5.6 then add h202. once a week add SM-90 if you want(if you want) or use it as a foiler spray(once ever 3days at most) but go research Dutch master for foiler spray!!!!
Once last thing.. I would go individual buckets instead of bin! You can create 3 nice plants under your growing room. but then again if done right with a good strain, u might only want 1 or 2 plants under your 400MH 2X2X6 Your MH is good for 4X4 and no more, unless your VEG.
Let me know more about how u work your system
and maybe pictuyres of your root system would be nice, hey!! Ill send you pcitures of my first root system done under my DWC system and you will laugh. ill just post them anyways lol.