Any ideas on this issue?

[cancareent]

Problem: see pictures
-Medium/grow method: Promix HP - CC
-Feed and supplements used: Dutch Masters Nutrient Line - half strength from feed chart recommendation
-Water source: RO/DI; tap- dechlorinated - PH - 6.2
-Strain : Red Poison -
Temp and Humidity : Day 77 / 40%.
Night 70 / 50%
- Light used: HPS DE 1000W 18/6
-Additional info: Two days since this

 

[Fakir710]

Problem: see pictures
-Medium/grow method: Promix HP - CC
-Feed and supplements used: Dutch Masters Nutrient Line - half strength from feed chart recommendation
-Water source: RO/DI; tap- dechlorinated - PH - 6.2
-Strain : Red Poison -
Temp and Humidity : Day 77 / 40%.
Night 70 / 50%
- Light used: HPS DE 1000W 18/6
-Additional info: Two days since this

How much soil in your pots?
How much you water?
What's your watering method?

Looks overwatered to me and those spots looks like water drops wich stayed during light time so light passed through drops as if they where convex glass so it burns the leaf.


Do you let your soil dry before you water again?

Regards and good luck.

 

[cancareent]

How much soil in your pots?
How much you water?
What's your watering method?

Looks overwatered to me and those spots looks like water drops wich stayed during light time so light passed through drops as if they where convex glass so it burns the leaf.


Do you let your soil dry before you water again?

Regards and good luck.

10 Gallon pots - 1 Gallon of water which gives runoff. I hand water, if the top is dry and when I stick a knuckle in the dirt and it feels like it is almost dry I will water- I dont let it get completely dry. Let me know if I am doing something wrong, thanks for taking the time to respond, I appreciate it.

 

[TanzanianMagic]

Problem: see pictures
-Medium/grow method: Promix HP - CC
-Feed and supplements used: Dutch Masters Nutrient Line - half strength from feed chart recommendation
-Water source: RO/DI; tap- dechlorinated - PH - 6.2
-Strain : Red Poison -
Temp and Humidity : Day 77 / 40%.
Night 70 / 50%
- Light used: HPS DE 1000W 18/6
-Additional info: Two days since this

They look a little crispy, however the leaves look most like this image of pH fluctuations.

https://www.growweedeasy.com/cannabis-plant-problems/ph-fluctuations

My guess is overfeeding, because unused nutrients will drag down the pH, especially if they also burn the roots and cause anaerobic decomposition in the rootzone.

It would be interesting to know what the runoff is, both pH and EC/ppm wise.

Also, the nutrients are cannabis specific, however the soil doesn't seem to be. Also, there don't seem to be a lot of nutrients in the Dutch Masters nutrient line. And Pro-Mix HPCC doesn't list any nutrients at all.

https://dutchmasternutrients.com/media-feed/
https://www.pthorticulture.com/en/products/pro-mix-hpcc-mycorrhizae/#tab:product-guidance

So it would be good to know what the pH and EC of the runoff are, to see if there is any buildup or very high EC that can point to burnt roots.

 

[Fakir710]

10 Gallon pots - 1 Gallon of water which gives runoff. I hand water, if the top is dry and when I stick a knuckle in the dirt and it feels like it is almost dry I will water- I dont let it get completely dry. Let me know if I am doing something wrong, thanks for taking the time to respond, I appreciate it.

No worries my friend, we here to help us each other!!
Sounds like you are doing it right, maybe a full plant picture would help a little bit more, did you dry the water drops after your waterings? That may cause the burns in the leafs, I usually let the fans run at max power after watering for 10 mins, so I'm sure the drops dry. Did you made any foliar spray?
Distance between plants and bulbs?
Edit* Sorry a couple more questions, I'm with @TanzanianMagic, some info about the EC would help, what the base EC of your R/O water? (without adding any nutrients, just plain water. )
Regards!

 

[cancareent]

They look a little crispy, however the leaves look most like this image of pH fluctuations.

https://www.growweedeasy.com/cannabis-plant-problems/ph-fluctuations

My guess is overfeeding, because unused nutrients will drag down the pH, especially if they also burn the roots and cause anaerobic decomposition in the rootzone.

It would be interesting to know what the runoff is, both pH and EC/ppm wise.

Also, the nutrients are cannabis specific, however the soil doesn't seem to be. Also, there don't seem to be a lot of nutrients in the Dutch Masters nutrient line. And Pro-Mix HPCC doesn't list any nutrients at all.

https://dutchmasternutrients.com/media-feed/
https://www.pthorticulture.com/en/products/pro-mix-hpcc-mycorrhizae/#tab:product-guidance

So it would be good to know what the pH and EC of the runoff are, to see if there is any buildup or very high EC that can point to burnt roots.

PH - 6.0 EC - 1.4
Thanks for the help guys

 

[TanzanianMagic]

PH - 6.0 EC - 1.4
Thanks for the help guys

In organic soil the pH through flowering should be closer to 7.0.

In ripening/flushing, it should be around 6.0 to increase absorption of micro-nutrients. However for flowering, you need more uptake of P and K, which happens best at a higher pH.

 

[Vanilla Phoenix]

In organic soil the pH through flowering should be closer to 7.0.

In ripening/flushing, it should be around 6.0 to increase absorption of micro-nutrients. However for flowering, you need more uptake of P and K, which happens best at a higher pH.

I agree. I’m in soil and I pH my feedings to 6.5
I’ll let my pH swing up from there, but I never go lower than 6.5
That’s in both flower and veg

 

[Creeperpark]

I have found that its best to run PRO MIX HP pH of 5.8 and the same goes for PRO MIX BX. Nothing went into my pro mix unless it had a pH of 5.8.

 

[Creeperpark]

I have a friend that is a consultant for Pro Mix, his name is "Troy Buechel". Go to YouTube and watch "Growing in PRO-MIX vs Soil or Hydroponics". The starting water pH is suppose to be kept at 5.5 to 5.8 with PRO MiX!!!!! If you are keeping your water and feed pH in the 6s you are not using Pro mix incorrectly. Thats why you are in Infirmary now!LOL

 

[Cantharellus]

Those plants look really small to be in 10 gallon pots ... how did you start them out ?

 

[NEED 4 SEED]

No worries my friend, we here to help us each other!!
Sounds like you are doing it right, maybe a full plant picture would help a little bit more, did you dry the water drops after your waterings? That may cause the burns in the leafs, I usually let the fans run at max power after watering for 10 mins, so I'm sure the drops dry. Did you made any foliar spray?
Distance between plants and bulbs?
Edit* Sorry a couple more questions, I'm with @TanzanianMagic, some info about the EC would help, what the base EC of your R/O water? (without adding any nutrients, just plain water. )
Regards!

How much soil in your pots?
How much you water?
What's your watering method?

Looks overwatered to me and those spots looks like water drops wich stayed during light time so light passed through drops as if they where convex glass so it burns the leaf.


Do you let your soil dry before you water again?

Regards and good luck.

The legend that water drops can burn leaves was disproved by a study someone had linked in another thread here. Let me look for the thread...


Here: https://www.icmag.com/ic/showpost.php?p=8747938&postcount=4