I always liked a big pH swing myself before I got pH Perfect nutes then stopped worrying about or testing the pH.
Before that mine would creep up to 6.3ish every 3 days when I did my top ups with RO then tested pH and ppm. I'd add some nutes to get the ppm to my target then add 4 or 5 drops of conc. sulphuric acid. Sometimes the pH would go as low as 5.2ish but I'd just leave it and it would be back to 6.3 or so in 3 days. Plants grew like weeds on steroids. Some nutes absorb better at different pH levels so with a swing they all got their time in the zone.
Personally I'd get your actual nute ppm to 3 - 400 and don't worry about much of the calmag. There's enough in the nutes to start with so a bit is plenty.
Wouldn't hurt to top feed using a turkey baster to run some nutes thru the pots as there's probably lots of small roots in there that aren't getting any food. A couple times a day until lots more are in the soup would help. I always have a small hole in the lids of my DWC tubs so I can get stuff in and out easy.
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