Is this your MelonGum grow? I'm not seeing that you measure your EC and in DWC, that's critical. Get an EC meter, they're pretty inexpensive - EC should be sitting somewhere around 1.6 - 2.0 or even higher since this is a photoperiod... You'll want to be pumping extra PK into her the more she gets into flower... and definitely some calmag (although not too much - maybe 1tsp in your bucket)... I don't grow photos - only autos and their feed requirements/tolerances are much less than photos but you can take a look at my diaries to get a sense of the balances of the nutes... growdiaries.com/diaries/154058-grow-journal-by-growinggrannie/week/867327 and growdiaries.com/diaries/157106-grow-journal-by-growinggrannie
Good luck!