Curlin on edges

[Imaginary Fiend]

This is my first post on ICMAG.COM so a big hello to all my cannabis loving compadres. I'm in the middle of my second grow and could do with some advice from the experts.

I'm growing 6 plants, all northern light and they are all 28 days in. All of the plants are looking relatively healthy compared compared to my first grow (Big Bud) but I have noticed that all of the plants are experiancing curling leaves at varying degrees.

The current setup is:
3 x twin auto pots connected to one 47 litre tank
Grown in Coco Coir
Using Canna Coco A&B, Canna Rhizotonic & CannaZym
EC = 1.6ms
pH ~ 6
110w fluro propagation light (6" from top of cannopy)
Humidy varies between 45% and 75%
Temperature varies between 17c at night and 26c during the day

I've read a few other posts on curling leaves and some people have suggested that low levels of light can cause this problem, which would make sense here considering my choise of light. I have a 600w hps bulb but I want to avoid using this until flower. If I am correct about the lack of light causing the curling my ideal choice would be to have a higher output CFL setup but I don't want spend the money unless I have to.

Any thoughts would be appreciated.

IF

 

[fifa]

I am very interested in your post, my seedlings had the same problem. Sorry I can't provide any helpful information or assistance I am a newb.

 

[Imaginary Fiend]

That's a good point actually fifa, my plants are also from seed.

 

[shaunmulok]

I'm no expert by any means but i always thought and have experienced similar looking problems from heat stress

 

[Imaginary Fiend]

Is heat stress really plausable considering the recorded temperatures and only 110w of fluro lighting? Unless the lights are too close to the plants?

 

[ibjamming]

I wouldn't sweat it...I've had plants do it too...and they came out great. Is there a fan blowing on them? Personally, I wouldn't be concerned...not yet.

 

[lysol]

1.6 ms is < 1ppm.

1.6 ec = 800 ppm may be too high

25c = 77F, optimal

 

[Imaginary Fiend]

I wouldn't sweat it...I've had plants do it too...and they came out great. Is there a fan blowing on them? Personally, I wouldn't be concerned...not yet.

Funny you should mention a fan. I do have one in the grow room now but it did go without for a few days while I put the fan to use in cooling me and my living room down. There's been no improvement since I put the fan back in a few days ago but it hasn't got any worse either.

1.6 ms is < 1ppm.

1.6 ec = 800 ppm may be too high

25c = 77F, optimal

25c is roughly where the temperature sits for most of the day so I'm fairly happy with that. I was under the impression that if I couldn't see any nute burn the the conductivity should be ok, but what do I know. I'll try backing off the nutes for while and see if that helps.

 

[dank.frank]

honestly, this does not fit the typical pattern of heat stress...to me this looks like the onset of some SERIOUS nutrient burning...I'd take it easy on the ferts a bit. From the looks of things, your tips are just starting to turn brown and "burnt"...caught it just in time, I'd say. A couple more days and you might have got them fried...hehehe.

Those are really young plants to be feeding that high a PPM....just give them some RO till you have some run off and then let them recover from the over-watering / flushing and then on your next feeding...keep it between 300-400ppm at most....

I could be wrong...if I am, someone will come and correct me...but that is my 2 cents...



dank.Frank

 

[tribeca]

I've only experience this using coco.I dont know if it was the coco that I did not flush properly or salt concentration.Its odd but quite a bit of people have ran into the same thing.Like frank said flush and cut back on your ppms.

 

[Imaginary Fiend]

SERIOUS nutrient burning eh? Those capital letters have scared me quite a bit so I'm starting my flush now. Not exactly what I had in mind for my Sunday evening but I guess a grower's gotta do what a grower's gotta do.

Could you explain RO? I'm familiar with what I have to do to flush them but still learning some of the terminology and acronyms being used.

Cheers,
IF

EDIT: I should probably point out that this is my first grow using both the autopots and coco. The big bud grow was in soil, no nutes during veg and hand watered. So I'm in unchartered territory at the moment

 

[lysol]

RO = reverse osmis, water that has been stripped of all essential minerals ( and consequently all non-essential minerals )

 

[darookie2000]

It looks like overfert, salt buildup (which I understand is common in coco), and/or overwatering (droop in the bottom right pot looks a bit like overwatering), unless it's a calcium deficiency (also common in coco - since coco releases potassium which will lock out calcium). How did the water get on top of the leaves on the bottom right? If you're misting, I'd stop. Coco can often have extremely high salt content (grows by the beach, so salty air = salty plant) on its own, so if you didn't wash it before you planted, you definitely want to leach it now (same fix as overfert).

 

[Imaginary Fiend]

I wasn't misting until about 5 minutes before I took the photos. The water on the floor is just spillage from being a bit clumsy when rotating the plants.

I did wash the coco before I started. Wasn't sure why at the time but had read that it was a good idea, so I did. I'm using the overfert theory for now so the flush is well under way. Not sure if it's relevant but I checked the EC of the runoff and it measured 1.4.

 

[darookie2000]

I wasn't misting until about 5 minutes before I took the photos. The water on the floor is just spillage from being a bit clumsy when rotating the plants.

I did wash the coco before I started. Wasn't sure why at the time but had read that it was a good idea, so I did. I'm using the overfert theory for now so the flush is well under way. Not sure if it's relevant but I checked the EC of the runoff and it measured 1.4.

The nice part about that solution is it works for salt buildup AND overfeeding. With coco, my understanding is that you are definitely going to want to give it a light feed at the end of the leach, because you aren't really supposed to feed coco with plain water unless you are trying to get the nutrients released.

I realized you were using autopots a little way into the previous reply which is why I went back and added that it might be salt buildup (reading is hard, lol ). Coco works more safely with drain to waste because of the tendency to pick up salts, so you'll definitely want to leach periodically to prevent the buildup.