Nutrient deficiency or light stress

[Stevenh82]

Hi, I'm currently on my first grow and loving it. I've got a few autoflowers 9 weeks in. Last week they had nitrogen toxicity so I flushed them with ph water. Now some leaves mainly at the top are turning yellow and brown. I feed them flora series, calmag every day at the recommended dose. Once a week I give them seaweed extract and also big bud at 2ml per litre for week 2-4. My run off is always about 6ph as is the water I feed them with, their grown in coco coir, roughly 970ppm which is a bit low as I've read it's to be 1000 but I'm using florals feed chart. Lights 18 on 6 off. Not all my plants have this soo I'm really puzzled. Any help would be greatly appreciated. Thanks

 

[GNick55]

can you take a photo from above the canopy?
things don’t look good.
do you see these kind of spots in other places? kinda white and fuzzy?

 

[Aqua Man]

What are your room temps? Highest and lowest.

Lighting and how close?

Drop feed to 800ppm

Likely not watering often enough. They look like they are pretty hot.

What kind of lights and how close?

You over fed then flushed so likely now they are hungry. You should always do a light feed after flush in coco.

What the ph and ppm of runoff?

How often are you water and how much?

What size of containers and did you add perlite?

 

[Stevenh82]

can you take a photo from above the canopy?
things don’t look good.
do you see these kind of spots in other places? kinda white and fuzzy?

Hi, I'm out just now but I'll take a photo when I'm home. No theirs no white fuzz or anything I've looked over them with magnifying glass. Some leaves seem a bit dry tho.

 

[Stevenh82]

What are your room temps? Highest and lowest.

Lighting and how close?

Drop feed to 800ppm

Likely not watering often enough. They look like they are pretty hot.

What kind of lights and how close?

You over fed then flushed so likely now they are hungry. You should always do a light feed after flush in coco.

What the ph and ppm of runoff?

How often are you water and how much?

What size of containers and did you add perlite?

Their in 5 gallon breathable fabric pots with 70/30 coco/perlite
Room temp is about 24 degree c all the time.
the lights are 18 inch from the canopy 18 on 6 off.
I've always watered them twice per day once in the morning and once at night. when I flushed them I gave them half feed for 2 days then 3/4 for 1 day then finally full on the 4rth day.
I cant remember what the run off ppm was I'll water them later and get back to you.

 

[Aqua Man]

Their in 5 gallon breathable fabric pots with 70/30 coco/perlite
Room temp is about 24 degree c all the time.
the lights are 18 inch from the canopy 18 on 6 off.
I've always watered them twice per day once in the morning and once at night. when I flushed them I gave them half feed for 2 days then 3/4 for 1 day then finally full on the 4rth day.
I cant remember what the run off ppm was I'll water them later and get back to you.

Ok check that next time both ph and ppm. Drop to 800 ppm and get good runoff. I would water morning and thats likely enough in that mix