Curling leaves

[KOA330]

Set Up:
- 600w HPS cool tube
- 4x4 tent
- 3 gal smart pots
- water every other day or when pot is light
- Feed nutes after watering twice ( feed -> water -> water -> feed )
- Temps: day 75f / night between 60-70f
- They've been on 12/12 cycle since 2/4

So I have three girls in my tent and the pics show what I thought would be my prize plant. The leaves on the tops are curling under really bad. The bottom of the plant doesn't look like this. Not just the tips are curling under but the leaves sides are curling in as well. My other two plants are looking great but this one, not so much. What could cause this? Any suggestions would be appreciated!! Thanks!

 

[hotrodharley]

Nitrogen toxicity. No nutes. Water, water. Then a reduced feeding at 1/4 strength. Add cal/mag per directions on whatever you go buy. Add that at 1/2 strength.

 

[OGkushNC]

What's your watering schedule? They look a bit over watered, also what's the actual dosage your using on your nutes?

 

[DANKSWAG]

Nitrogen toxicity. No nutes. Water, water. Then a reduced feeding at 1/4 strength. Add cal/mag per directions on whatever you go buy. Add that at 1/2 strength.

Not just any you buy, there is a technical difference between cal/mag for soil and cal/mag for hydro. Soil should get cal/mag from a carbonate solution, i.e. General Organics Ca/Mg+. Hydro growers should use a nitrate based ca/mag i.e. Botanicare Cal Mag Plus.[h=1][/h]

 

[personal lux]

anyways its obviously NOT nitrogen toxcity. he using nutes every third watering lol. this is OBVIOUS heat damage. your plants are inches from your light in the picture. i can see that the buds are airy because tis obviously too hot where they are. its about radiated heat from the light. put your hand by them you will see

 

[personal lux]

anyways its obviously NOT nitrogen toxcity. he using nutes every third watering lol. this is OBVIOUS heat damage. your plants are inches from your light in the picture and r only effect on the top portion of plants.. i can see that the buds are airy because tis obviously too hot where they are. its about radiated heat from the light. put your hand by them you will see

 

[KOA330]

anyways its obviously NOT nitrogen toxcity. he using nutes every third watering lol. this is OBVIOUS heat damage. your plants are inches from your light in the picture. i can see that the buds are airy because tis obviously too hot where they are. its about radiated heat from the light. put your hand by them you will see

I carefully tied down the main branches in order to get them further away from the light. Is this leave curling something that can be fixed? I did that a couple days ago and they look no different. I have two other plants in my tent and they're both looking good. Is there another possibility as to why this may be happening?? How much should I be concerned?