Nutrient burn or light stress

[benjones]

Hi THCfarmers . I have this slight tip burn all along the edge of some of my plants . I had the same thing on my last grow and I couldn’t figure out what it was . Both times it seems to have happened after I put the lights power up to 85-90% at 13-15 inches away ( mars hydro fce4800 , 480 watts ) . These are 4 weeks into flower . I will try and find the other thread where I had the same problem .

Any idea what this could be guys ?

 

[benjones]

Water going into the coco is 1.6 and coming out is 2.0 ( it rose in the last 2 weeks ) . Ph is 6.0 in 6.5 out

Last feed was 1.2 and the run off came down to 1.9

Temp 25c
Rh 60 .

I have a dehumidifier coming in the next day or 2

 

[benjones]

Is this a deficiency of some kind?

Hi all . Some of my plants have this yellowing the the edge of some of the leaves . Could it be a deficiency or possibly light burn ? Thanks

www.thcfarmer.com

that was what happened on the last grow, it kind of looks like i am having the same issue and i would like to try to fix it before it gets as bad as it did last time . many thanks for reading

 

[Zen_Seeker]

Take a pic of the full canopy.

No spots or droopy leaves. I see yellow leaves, some canoeing. Heat stress, before burning sets in? 🤷‍♂️

 

[benjones]

1 sec mate , i will take a photo

 

[Zen_Seeker]

I see you had epsom in your last grow, still using it? Approximately 15ml per 3.75L.

Fishing for why it’s yellow... unless it’s just the colour of the photo lighting?

 

[benjones]

 

[benjones]

I add 1 gram a gallon of Epsom salt per feed

 

[Zen_Seeker]

Much better. Now others will have a look and comment.

Yellow doesn’t seem to be an issue in these pics.

Looks like you’re doing better than me bud!

All I can see is a touch of canoeing at a few tops and maybe missing some Epsom if that’s striping on the newer leaves.

How’s the heat at canopy top? You got a small fan to circulate air?

 

[Zen_Seeker]

I add 1 gram a gallon of Epsom salt per feed

I work in metric or cooking terms for this. Imperial is for construction only. 😝

15ml = 1 TBSP
1g = ?

I’m not a Coco guy but there are a few good ones here. Search and maybe reach out to one if you don’t get any helpful replies.

 

[benjones]

ahh sorry mate, i am unsure what it is in ML or teaspoons 🙂

thanks for the compliment

heat at the canopy is the same as the room, about 25c . i have a wall fan and a fan on the floor so there is good air movement . i am just unsure if this is because i raised the power of the lights or if it is nute burn . it doesn't seem to have affected the lower growth

 

[Zen_Seeker]

ahh sorry mate, i am unsure what it is in ML or teaspoons 🙂

thanks for the compliment

heat at the canopy is the same as the room, about 25c . i have a wall fan and a fan on the floor so there is good air movement . i am just unsure if this is because i raised the power of the lights or if it is nute burn . it doesn't seem to have affected the lower growth

Unless really bad heat/light usually only seem to affect the top, at least at first.

So air is good.

If you mean the tips have a slight nutes burn that shouldn’t be an issue. Just back off a hair on feeding.

If light is the only change then try putting it down a bit at least until a Coco or staff member can advise.

What do you see as being an issue? They look pretty good from what I see.

 

[benjones]

I have slight tip burn which isn’t too bad , but along the edges I also have some kind of burn starting , if you see my thread I posted above on my last grow it got a lot worse . I would like to prevent it happening again if I can

 

[Aqua Man]

Back the light up just a couple inches and add a feeding. To me i tuink you need to increase feed frequencies

 

[Aqua Man]

I have slight tip burn which isn’t too bad , but along the edges I also have some kind of burn starting , if you see my thread I posted above on my last grow it got a lot worse . I would like to prevent it happening again if I can

Aounds like very early k deficiency but just try increasing the feed frequency

 

[benjones]

@Aqua Man hi mate I hope you’re well

I feed every 2 days . They are in 5 gallon pots . Should I feed everyday ?

 

[Aqua Man]

@Aqua Man hi mate I hope you’re well

I feed every 2 days . They are in 5 gallon pots . Should I feed everyday ?

Id give that a try… feed about 30 min or so after lights on if possible.

 

[benjones]

Thanks @Aqua Man

20% run off ?

 

[Aqua Man]

Thanks @Aqua Man

20% run off ?

well for 5 gal WITH perlite id say feed 1.L or a touch more and you want to see about 100-200ml of run off.

if you get that amount of runoff from 1L then your good

 

[hillbil]

GrowWeed Easy has a section called Plant Doctor for good info on LED light stress. Very helpful.