The main concern is you don’t add to many extra’s to the tank… Making your Ec to high with the extra’s…
In the past when I added to the Grobo I would do a drain / fill… wait for grobo to dispense all nutes and let it mix… Then I would remove a couple litres of nute water and replace it with water with extra’s added… Doing it this way you can control how high your Ec is… You plant already looks on the high side for nutes to me. I just don’t want to see you burn her.