Magnesium Deficiency? Help!

[Palmettoman]

So my 7 autos are beginning to flower, I noticed a few leaf tips starting to turn up a bit and over the past 2 days this has happened. I would like options on this please. My 20 other plants are photos and they’re not doing it but they also aren’t flipped yet. Soil is 50% FFOF and 50% FFHF.

 

[crimsonecho]

Potassium deficiency. Don’t know your prefered method but add more flowering fertilizer (i use compost teas with banana ashes as one of the ingredients and top dress with the sludge seem to work for me).

Edit: i read somewhere that those burned edges also could be from potassium deficiency and not from nute burn. My autos were heavy feeders never burned them with top dressing and compost teas which i was very generous with.