AsNoriuanswered grow question 2y 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.