@PharmaZ,
I use 81% phosphoric acid, tap water is around 7.2ph and 0.25ec, I added calmag till 0.4ec then 5:5:10 bloom nutes till 1.2ec which worked out at around 4ml per liter, half the bottles recommended 6-8ml.
I used the phosphoric acid after changing nutes, it took only 2-3ml to bring my 100L res to around 6ph.
Roots are visually healthy at least, slightly off white and strong, no slime, smell or anything.
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