Edges of big fan leaves turning purple/black - 4th week flowerin - blue cheese - pics

Before i start i'd like to say i have read through plant moisture symptoms and the plant problem guide thingy. I have tried researching this problem but so far havn't found any useful information.

Up until yesterday this plant was in perfect health. Then i fed her a feeding of full strength nutes including a splash of cal-mag which i dont usually include in my feedings but chose to use it yesterday for some reason. about 6 hrs later, i came back to check on them and the tips of the big fan leaves were curling UP, and the leaf edges were getting purple/dark brown/black.

Next to this plant sits a Sour Diesel, and until now both plants have been on exactly the same feeding schedule. This is the first problem all grow, and its only on the blue cheese plant. The sour D is in perfect health. Since yesterday i have flushed her with x3 volume of plain water, and today gave here some half strength nutes. So far from what i can see the problem has not developed and has not spread. These dis-colourings can only be seed on a few fan leaves on each of the 8 main branches.

Grow info:

All my grow info can be seen in my journal in my sig if you want to know what ive been feeding ect.

At first i thought it was nute burn, but these symptoms are not appearing on the lower leaves, only on the top half of the plant, so i don't know. There are no heat issues, no overwatering issues due to a lot of drainage, and each time i water i make sure a good few litres comes out the bottom of the pots.

Any info would be useful. Whilst i'm not worried about the state of the plant as it looks like i caught it very early, I'd like to know where i went wrong and what the cause/solution is.

Thanks

Last 3 images are of normal leaves/the plant before the full strength feeding last night

I think you may be a hair hot with the feed but the overall health of the plant is just fine. She's a pretty one too!! The purpling on the edges is normal. Sometimes the chlorophyll hues change as the plant shifts gear. Chlorophyll can show as red or purple (hence all the purple strains). It usually requires a slightly cooler temp but it's not always necessary. I would just monitor her but wouldn't fret too much. Certainly don't change anything other than backing off the hot aspect of your feed regimen just a tad. Good luck!!

Yeh seems to be the most common answer, its biobizz allmix, and i dont measure the PH, maybe i shud.

This purpling definately isnt natural, the damaged leaves are very slightly worse than yesterday but i dont think its spread to any newer growth. Thinking these leaves will eventually die off. Will feed plain water next time with molasses, hopefully sort her out.

Anyway thanks for the suggestions.

Based on the shape of your leaves i would say the ph is a little out of whack, so i would pay more attention to that, but other than that they look healthy.

as far as watering until a few liters comes out the bottom, that's a little overkill, one liter out of the bottom would be more than enough.

Robert Paulson said:

Based on the shape of your leaves i would say the ph is a little out of whack, so i would pay more attention to that, but other than that they look healthy.

as far as watering until a few liters comes out the bottom, that's a little overkill, one liter out of the bottom would be more than enough.

Click to expand...

Yeh i wouldn't be surprised at all, will probably invest in a PH meter for next time. I only water like that due to the pot having 16 drainage holes and the size of my resevoir. Figured i might as well use all the batch i've mixed, its only gona replace old nutes with fresh ones. Since the problem has continued slightly i'm probably gona give her a good plain water feeding today with molasses in it, hopefully this'll wash out any excess nutes in the soil and at the same time prevent her from being starved of anything. The buds are still growing though i think, i just dont want any more leaves affected/getting worse.

If anyone was wondering this was a caused due to feedin her too strong nutes, or feeding her nutes too regularly, either way she was gettin too much