Leaf edges curling up

* Soil (not sure on brand, but looks pretty good)
* 600 watt hps (sitting probably 2 feet from tops)
* Soil pH appears to be the same as what im feeding it (6.5) based on runoff test.
* Temperatures range between 68 - 82 depending on time of day, averaging in the middle (and has been the same through out the whole grow, so i don't think it is temperature related otherwise these symptoms would have appeared earlier)
* Fed 12ml of this in 3 litres of water a day or two before curling started to appear; Thrive Concentrate All Purpose Plant Food - Yates products (prior to that, it had only been plain watered and once fed a very weak mix of an organic fertilizer when slight yellowing started to occur).


I'm not sure whats going on here. It is important to mention that this is the same plant that i posted about a few days ago with a suspected deficiency of some kind; https://www.rollitup.org/marijuana-plant-problems/315300-new-growth-yellowing.html

So in response to that, i fed it the 12ml of said fertilizer which was slightly lower than the suggested amount on the bottle (5ml/liter regular rate, and 10m/liter occasional rate). I've used it before and never had any problems with it although i cant remember how much i was mixing. But now, on top of the yellowing (which remains a problem) - im getting this curling going on, particularly in the new growth).

Im thinking either nute burn, or maybe magnesium deficiency (which is what i suspected when posting my other question). There is a problem with the nute burn theory; i have other plants in the room which are showing the same kind of curling on the new leaves (but to a lesser degree) which have not been fed. So unless you can get nute burn from just your soil mixture then this poses a problem for nute burn as explanation.

Anyone have any ideas?

First,I don't see any leaves curling up,if they are it could be from some kind of nute burn/def. or heat issues which i read you dont have. Your plants look fine,looks like you either watered or fertalized a day late from the second pic but they look good,keep up the ferts,and the grow. Goodluck.

Look at the leaves in the new growth, they are curling up like taco's.

I know it may not look too bad now, but i want to get in early with these problems i dont want to wait until the whole plant is on the verge of death before i act :/

There is a problem here not only with the taco leaves but also the way all the leaves are slowly turning lime green.

curling up like tacos is a sign of either heat stress or overwater. In my case, it was both of these. Let them dry out and back the lighting off a bit. Give em a couple days or less and see if they perk up. Mine did, so good luck

oh and by the way. When leaves start to taco, they are trying to hide from the light by only exposing a minimal amount of leaf. This was something I learned when I was using MH and HPS. I use all T5's now for veg and it has worked out wonderfully. I can put my 4 foot 8 lamp light inches away with no problems.

That does make alot of sense. Cool ill raise the light a bit and see if that helps.

Cheers man

Problem seems to have been resolved. At least, they are looking alot better and it definitely has not got worse.

I'm not sure whether it was the heat or whether it was just responding to the nutes i had fed it, which fixed another problem i had at the same time (https://www.rollitup.org/marijuana-plant-problems/315300-new-growth-yellowing.html).

nizmo said:

Look at the leaves in the new growth, they are curling up like taco's.

I know it may not look too bad now, but i want to get in early with these problems i dont want to wait until the whole plant is on the verge of death before i act :/

There is a problem here not only with the taco leaves but also the way all the leaves are slowly turning lime green.

Click to expand...

Those leaves curling are your fresh sprouts,this accours sometimes when your plant is growing really fast and good,I do hydro and I see it all the time. I wouldn't say it's overwater,or nute prob. or anything because your plant looks healthy. That lime green is caused from your plant being deprived nitrogen and then getting it thats why it looks green on the outside edges but not at the beginning of your veins. Your plant is fine dont worry.