Hallo! Yellowing leaves on 1 of 2 plants

[Not-a-cop]

Problem: So i have 2 Fast buds star dawg growing in the same tent, under the same lights, same conditions and same nutrient schedule, yet one is showing yellowing of the leaves, i thought it was a potassium deficiency but i'd like an experts advice. i have also raised my lights by 4 inches or so in case this is light burn
-Medium/grow method: Soil - Biobizz All Mix
-Feed and supplements used: Biobizz Biogrow & bio bloom per below schedule + 1ml/l vitalink calmag + misted every day with 1ml/l calmag solution

-Water source: tap water, 50ppm on 640 scale is around 0.04EC, there's not a lot in it
-Strain and age stardawg by fast buds, germinated on 27th march so around 5 weeks
-Climate: lights SP250 18hrs kept at a temp of 25 - 27 celcius, lights off temp drops to around 16 celcius
- Light used: mars hydro sp250 18/6
-Additional info: symptoms appeared quite quickly, some calmag deficiency early on corrected by using 1ml/l in the feed from wk4 and foliar applications each day at 1ml/l and while lights on (is that an issue?)

one point to note, its twin, is perfectly healthy despite the same calmag issue i mentioned (i have photographed it below for your opinion so you have a complete picture). one last thing, they were topped and lightly LST'd

thanks in advance for your advice!

This is the defect:

below is the pervious calmag deficiency which i think did not progress after i corrected the feed and began daily foliar application by misting

Close up of a brown spot and leaf curled down slightly which may or may not indicate something:

finally, the complete plant:

 

[Mañ'O'Green]

Problem: So i have 2 Fast buds star dawg growing in the same tent, under the same lights, same conditions and same nutrient schedule, yet one is showing yellowing of the leaves, i thought it was a potassium deficiency but i'd like an experts advice. i have also raised my lights by 4 inches or so in case this is light burn
-Medium/grow method: Soil - Biobizz All Mix
-Feed and supplements used: Biobizz Biogrow & bio bloom per below schedule + 1ml/l vitalink calmag + misted every day with 1ml/l calmag solution
View attachment 1313698


-Water source: tap water, 50ppm on 640 scale is around 0.04EC, there's not a lot in it
-Strain and age stardawg by fast buds, germinated on 27th march so around 5 weeks
-Climate: lights SP250 18hrs kept at a temp of 25 - 27 celcius, lights off temp drops to around 16 celcius
- Light used: mars hydro sp250 18/6
-Additional info: symptoms appeared quite quickly, some calmag deficiency early on corrected by using 1ml/l in the feed from wk4 and foliar applications each day at 1ml/l and while lights on (is that an issue?)

one point to note, its twin, is perfectly healthy despite the same calmag issue i mentioned (i have photographed it below for your opinion so you have a complete picture). one last thing, they were topped and lightly LST'd

thanks in advance for your advice!

This is the defect:
View attachment 1313700

below is the pervious calmag deficiency which i think did not progress after i corrected the feed and began daily foliar application by misting
View attachment 1313708

Close up of a brown spot and leaf curled down slightly which may or may not indicate something:
View attachment 1313702

finally, the complete plant:
View attachment 1313704

Too much fertilizer.

 

[Not-a-cop]

too much? of which nutrient?

 

[Not-a-cop]

i've followed the biobizz NS to the letter of the law (by jesus mary and the wee donkey) one plant is dandy, the other is showing as above

 

[Mañ'O'Green]

i've followed the biobizz NS to the letter of the law (by jesus mary and the wee donkey) one plant is dandy, the other is showing as above

Most growers that post here report that the Bio-Bizz all mix is to hot for autos to start with then you are following a schedule that might work for photoperiod plants but the Stardawg is an auto. Autos generally only need about 50% to 60% of the fertilizer of a Photo. So I think it is too much of all the fertilizer not just a single element.

 

[Not-a-cop]

Cool thank you for explaining that to me, I wasn’t aware that biobizz had that reputation, I’ve never used other nutrients but maybe next time I’ll look into alternatives.
So would your advice now be to feed just plain tap water & calmag for a while?

what’s your take on misting calmag in the way I mentioned above?

 

[Bill.de.Cat]

.....couldn't find the culligan man girl, lol.

 

[tronN00dles]

I seem to be repeating myself on this forum lately, but I truly believe those rust spots are a sign of calcium toxicity, and those yellowing edges are a potassium deficiency caused by excess calcium. Foliar applications of calcium every day? No need of that. Sounds like you overcorrected.

On the plus side, these plants are hardy af. Settle down on the calcium, give an extra plain watering or two, and hopefully things will improve.

-tronN00dles

 

[Not-a-cop]

Thank you. Ok so my go forward plan is now to stop foliar calmag and feed only 1ml/l calmag for a week or so, I’ll update next Tuesday (or before if it all turns to shit)

I did notice that my plants like being misted daily, so I’ll continue with that albeit with just plain tap water.

 

[Not-a-cop]

Anyone want to stab a guess at what’s causing this on my other plant? The one that was perfectly healthy until two days ago