DWC M-L Strawberry Lemonade First Grow

Howdy, So this last week has been about learning, quickly. Plant 2 has been suffering from yellowing, I noticed that at first it was a darker green than plant 1 - (first signs of Mg deficiency I have since learned). As plant 1 was doing so well until a few days ago, I originally assumed that plant 2 was just a bit of a slacker. I think basically it is more susceptible to PH differences than plant 1. First mistake was not knowing about the benefits of PH range... What I did not know earlier in the week is that Mg and Ca are only absorbed efficiently at 6.0 and above, my OCD kicked in and I refused to let the PH wander above 5.7; as from what I have read in forums, 5.7 is the sweet spot. Main lesson from last week is that I'm not going to be so anal about PH levels, I will let the PH rise to 6.3 before I drop it back down to 5.7, this will give the plants and window of time to grab hold of some well deserved CalMag before I drop it back down so it can retrieve some Mn and P if it needs any. My plants told me they were in need of Calcium over a week ago, but I naively thought that maybe I spilled a droplet of water on one of the leaves, and that caused it to burn. As I was adding CalMag+ to the solution when I replenished the reservoir. My second mistake was panicking... After realising above, I bombed the nutrient solution with 35ml of Cal Mag, bringing up the PPMS to 460, this subsequently gave the strongest plant nutrient burn. On top of this, I gave both plants a foliage spray during lights out with some diluted CalMag as well. So anyway, the main thing I have learnt is when the plants are ill, its probably best to take it easy, do a res swap at the very worst and concentrate on my PH levels first before throwing more variables into the fray. Positive notes: Plants 1 & 2 is now working on their 5th node, I know I am technically allowed to top at this point, but I am going to wait until they are working on their 7th before doing anything, this way I will be able to tell if the new growth is looking healthy, and my investigations are correct. I have now installed a Hailea 150a, with a submersible pump, this is now keeping the reservoir at 20ºc and its keeping the nutrients well mixed, I'll post a video later this week showing the set up. The roots at the top look a little dark, but I have done a sniff test and they don't smell at all, I think it is just where some of the tea has built up where the bubbles meet the air. Roots do seem rather large, maybe they have stretched so far looking for Mg and Ca :P Decided against increasing PPMS, going to do another week, so 5 weeks veg, gives the ladies some time to recover. Trimmed the burns off of leaves mainly so I can keep a track to see if damage is continuing. Anyways, I hope the above makes sense and draws other newbies attention towards PH ranging for hydro; I have posted a pic which shows the PH range for each important element. Thanks! 😊