Strange crispy brown leaves?

[Seawolf]

Hi all 

 

Im back once again because something else has gone wrong  

 

My issue is that my girls over the course of a day or so started developing brown/copper colour crispy leaves - this is after a 3ML bloom feed 4 days ago and a 1ml veg 2ml bloom and .5ml calmag feed yesterday

my light is 18cm from canopy and this strange discolouration appears on 1/3 of the plant from the top - I suspect this might be nute burn/light burn (as i recently lowered 250W LED light from about 22cm) but also shares similar symptoms as phosphorous deficiency so im not sure on what to do here as either one can really escalate the situation if its wrong 

 

Im hoping someone is able to help maybe @blackpoolbouncer @Shumroom ?

 

below is my setup

 

 

growing in canna terra pro soil ( in 11l pots)

Week 7 of grow

18/6 schedule

Temps light on - 22-27

Lights off 20-22

RH lights on - 40%

Lights off 50%-70%

soil temp 22c-23

[Caly]

Are you in flower? But your light schedule is 18/6?

[Wacky Wardrobe]

Just now, Caly said:

in flower? But your light schedule is 18/6?

It's the autoflower section Caly  :-)

 

A tad too much light methinks @Seawolf.

DLI and all that.

[Seawolf]

My mistake, i meant light was at 22 inches now its at 18

[Caly]

8 hours ago, Wacky Wardrobe said:

It's the autoflower section Caly  :-)

 

A tad too much light methinks @Seawolf.

DLI and all that.

Thanks mate my bad

[Wacky Wardrobe]

8 hours ago, Seawolf said:

light was at 22 inches now its at 18

You could do with knowing approximately how much light they're actually getting.

I suspect too much.

 

There are free apps for smart phones that use the camera's light sensor to measure light intensity.

I use one called Tent Buddy.

 

You tell the app how many hours a day the lights are on and then measure the light hitting the canopy. The app can calculate what's known as the DLI.

It's a bit like the plant's calorie count per day. The app tells you what sort of DLI you should be aiming at for the various stages of growth.

 

Light hanging heights or intensity for plants flowering for 12 hours a day are different to running them for 18 hours.

If your light is at the right height to flower photo period plants at 12 hours it's going to be too close at 18 hours.

 

It's a bit like eating a pack and a half of biscuits per day instead of just one.

You can have too much of a good thing.

:-)

[highgrower]

I agree too much light - if leaves droop like that and its not over/under watered the leds are too intense for it.

 

Below is an example of what happens for me - leaves starting to go a bit off colour as well as drooping - just got a new light so still figuring out hight / watts for it but it was too much for it:

 

[Seawolf]

Thanks all - I think its a combination of me moving the light closer and too much feed maybe? I moved the light so they only get about 75-90k lux (before it was 115k lux) and i think i should do a flush as the plant that i gave 1ml more bloom to seems to be doing the worst out of the 3 

[highgrower]

Dont flush just dial down the light wattage or move the light further away.

 

Maybe dial down on the grow a bit and up the bloom plus dont give bloom one watering and grow the next just give them a mix of bloom and grow all feeds (assuming biobizz nutes if just one bottle bloom like organix then need to feed them just bloom every water)

[Seawolf]

Just now, highgrower said:

Dont flush just dial down the light wattage or move the light further away.

 

Maybe dial down on the grow a bit and up the bloom plus dont give bloom one watering and grow the next just give them a mix of bloom and grow all feeds (assuming biobizz nutes if just one bottle bloom like organix then need to feed them just bloom every water)

Thanks for the advice!

 

I find it really hard to dial in the bloom/grow nutes ever since flower started, one day the plants are happy with 3ml bloom and the other they wilting after 3ml bloom? Then i get confused if im giving too little and causing deficiency or too much and causing nute burn... 

 

The reason why i thought its nute burn is because i fed them and lowered the light at the same time so to my understanding more light= more nute uptake which might have caused the dying off? 

 

Also is it normal that these girls are looking as if they want more water every 2 days? I water 2l every 2 days at this point with a fair bit of run off and they just seem to drink it up as if theyre 3 meter long plants - First grow so i guess  this is a trial so i can learn of the mistakes 

[highgrower]

11 litre pots will need about 2 litres of water per watering.  Depending how rooted out and much evaporates (like fabric or air pots do dry faster) every 2 days is not unreasonable.

 

Try to be consistent with watering and nutes - ie dont jump about from grow to bloom and just slowly increase from a few 1-2ml a litre up to about 4-5ml depending on where you are in flower and the nutes your using as the weeks go on and then back off around when plants are a few weeks from finishing.

 

Dont think about flushing or anything like that as your in compost and will just do more damage than anything else.

 

I think the higher lights just push the plant too much and it gets burnt so not necessarily it getting through the nutes any more.

 

 

[Seawolf]

Awesome, thanks for pointing that out the jumping between nutes must have made things unbalanced! its 2l in plastic square pots so i was very surprised that they take so much 

[Herbal Kint]

It would help if that picture was with light off,looks hungry to me.

[Herbal Kint]

To add with 3ml bloom I doubt it's P deficiency,if you want to rule out MG def here are mine MG def autos,think it goes to worse on next page you can compare damage.

 

[Herbal Kint]

Your looked more like this,that's N hungry critical plus about same age as yours,plants started to go pale on middle and bottom first.I up the food a bit and it finished nice

 

Edited May 12, 2022 by Herbal Kint