Purple lemonade problems

Have added some cal mag to my feed schedule. Hopefully this helps

Indeed, looks like mg deficiency. Look up '' cannabis deficiency chart'' you can see for yourself ;)

pH problems? What soil are you growing in? Provide more details, amount of watering, type of soil, pH of your water, temperatures, outdoor or indoor?

Looks like needs some Magnesium. Put a 1/8 of a teaspoon of epsom salts in a litre spray bottle and shake well. Spray the plant down under and on top of the leaves when lights go out. Best of luck on the grow.