AsNoriuanswered grow question a year ago N toxicity and lockout. I see start of magnesium too.
Plain water with run off. Try to load 1.5 liters of 6.3 phed water when you water next rime. Count days, if it takes longer than 5 to drink up, decrease by 20%
Dont let them stand in run off, collect with sponge and throw out.
Any calmag will have N, epsom salt too. Would not use, till new grow goes lime green, not yellow green or just dont grow and stays dark green.