He wanted to get rid of stunting and curling of specific plants. He found that lowering the NO3-dosing made it.

Was he wrong? You can't explain this by saying "it never happened to me".

Me personally can fix it by stop dosing KH2PO4 - always when I've tried to up the PO4-dosage some plants curled up (L. glandulosa, L. inclinata, A. reineckii) and ran EI all the way and the tank looked good enough to give me placing in contests. But those curled and stunted new tips on those plants are going to make me crazy.

EI clearly is not the way for those plants for many people with low KH.

The answer I guess is to get some bicarbonate (I'm using dolomite which clouds the water).. Would *love* to know why low KH and inert substrate cause this..