Leaf tips curling and black

[sureshot66]

Coco beds
temp 83 humidity 55
Week 5
Ppm 1900
Ph 6
Co2 1500
Runoff 2300

Never seen this anyone know what's up?
This is happening only on 2 strains orange glue and stardog which I've run both before at these same numbers...I have numerous other strains in this room and they're all killing it...There's no wilting on the affected plants they look great but they have this black on the leaf tips and curling upwards,the affected spots are brittle and crumble ..I did just give them a strong feed but as I said I run these numbers all the time in multiple rooms and never an issue ....I started flushing these trays today...no foliar spraying has been done in weeks...anyone? Thanks

 

[Jellyfish]

Never seen that. Good luck.

 

[sureshot66]

Never seen that. Good luck.

:/
thanks anyway

 

[Thcvhunter]

Do you use rockwool?
Could be fungal

 

[corky1968]

Never saw that before but a slight increase of humidity may help.

Go for 60-70%.

Good Luck

 

[sureshot66]

Do you use rockwool?
Could be fungal

coco beds theres 12 trays, 6 rows or zones of 4x16
its only on zones 1 and 3
and theres also some mendobreath in zone 1 that are unaffected...

 

[Flyingteapot]

Looking like nitrogen toxicity

 

[xxxstr8edgexxx]

Looks like a physical burn. Like a flame liked it. I know that's not it but the way it died green and didn't fade and it's an anrubt line seperating nice green growth and desiccated green tissue that looks as though it was healthy when everything north of the line is dead. I've seen that with flamevtouched leaves. Was there any solvents being used close to the plant. Is it the whole bed uniform or just a section of the bed.

 

[ozzieAI]

check your roots..is this happening to the older leaves first then working it's way to newer growth?

 

[TanzanianMagic]

Coco beds
temp 83 humidity 55
Week 5
Ppm 1900
Ph 6
Co2 1500
Runoff 2300

Never seen this anyone know what's up?
This is happening only on 2 strains orange glue and stardog which I've run both before at these same numbers...I have numerous other strains in this room and they're all killing it...There's no wilting on the affected plants they look great but they have this black on the leaf tips and curling upwards,the affected spots are brittle and crumble ..I did just give them a strong feed but as I said I run these numbers all the time in multiple rooms and never an issue ....I started flushing these trays today...no foliar spraying has been done in weeks...anyone? Thanks

[URL=https://www.icmag.com/ic/picture.php?albumid=69122&pictureid=1644756&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=69122&pictureid=1644757&thumb=1]View Image[/url] [URL=https://www.icmag.com/ic/picture.php?albumid=69122&pictureid=1644758&thumb=1]View Image[/url]

Humidity is a bit high. Looks like P lockout/deficiency (curling up leaf tips) with K def thrown in (purple leaf stems). And with the high humidity, the damaged leafs could turn moldy.

Deficiency or lockout is hard to tell. Not enough P/K at the start of flowering. Or low temperatures at the root zone. Overall the temp of 83F is ok but a little high 65 to 77 would be ideal.

 

[SamsonsRiddle]

Humidity is a bit high. Looks like P lockout/deficiency (curling up leaf tips) with K def thrown in (purple leaf stems). And with the high humidity, the damaged leafs could turn moldy.

Deficiency or lockout is hard to tell. Not enough P/K at the start of flowering. Or low temperatures at the root zone. Overall the temp of 83F is ok but a little high 65 to 77 would be ideal.

not to argue, but maybe you missed the fact he is using co2