I used regular nutrients with no magnesium additive and don't get deficiency. Most people who get deficiencies are actually not managing their pH. If you keep pH at 6.5, you won't get deficiency of anything. If plants have issues at 200 PPFD something is majorly wrong. I'm guessing its pH.
I...
5 lbs of mids vs 1 lb of fire would not be determined by 1 variable
in the real world, the spectra would result in 5.1 lbs of 27% THC vs 4.9 lbs of 25% thc.
and no one knows it hasn't been studied.
too much ph down. thats your problem. don't worry about letting the water sit out for 24 hours.
just give them 6.5ph from now on and it will get better.