Retarded leaf growth, maybe genetic.

[Hovz]

Notice the leaf curls down in the last one

SOIL:


How long has this problem been going on? like a week
What STRAIN are you growing?unknown clone
What was the establishing technique? (seed or clone?)clone
What is the age of your plants?1 month 15 days
How long have they been in the soil mixture they are in now? they're entire life
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before?yes
How Tall are the plants?13 inches
What PHASE (seedling, vegetative or flower) are the plants in?veg
What Technique are you using? (SOG, SCROG etc)none?
What size pots are you using? (Include how many subjects to pot) 3 gal grow bags
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) happyfrog mixed with chunky perlite
What brand Nutrient's are you using? sunleaves guanos ( havent added any yet)
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* i've used maxicrop kelp 1/2 tsp to a gallon and some liquid karma according to directions on the back.
How often are you feeding? once they dryout , 3 days approx
If flowering, when did you switch over to using Bloom nutrients?
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
What is the TDS/EC/PPM of your nutrients used?
What is the pH of the "RUN-OFF"? idk
How often are you testing pH/ppm/EC/TDS? not often
What method of pH test was administered? Using Strips? pH pen?
How often are you watering? 3-4 days
When was your last feeding and how often are you feeding? i gave them maxicrop and liquid karma once.
What size bulb are you using?600w hps
How old is your bulbs?new
What is the distance to the canopy?20" glass sealed hood
What is your RH Factor? (Relative Humidity)35%
What is the canopy temperature?70 F
What is the Day/Night Temp? (Include fluctuation range) 65-80 daytime nightime 60-65
What is the current Air Flow? (cfm etc.)440 cfm
Tell us about your ventilation, intake exhaust and when its running and not running ?exhaust thru filter thru hood out the tent
Is the fan blowing directly at plants? my oscilating fan broke
Is the grow substrate constantly wet or moist? no
Is your water HARD or SOFT? hard
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? tap
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?(Only if you have a tds pen) i believe around 250 i can double check that
If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives?(Only if you have a tds pen)
Are you using water from a water softener?no
Has plant been recently pruned, cloned or pinched?no
Have any pest chemicals been used? If so what and when?no
Are plant's infected with pest's?no

 

[the END]

Heat possibly?

edit: He must've added that questionnaire after I posted!.. ...Or i guess i did miss it lol

 

[KMothsi]

^^^Except the author of the post said his heat ranges from 70-80, so no problems there.

That can be from heat, but you're heat looks good. Or possible stress from nutrient strength. Or, as you guessed, genetic. But, my best guess, and the most likely scenario is pH problems. Test your runoff to see where that is falling. Mix up the pH of the solution you feed to different plants and see if the results change. Leaf warping like in the pictures you show tells me that your plant is either experiencing wild fluctuations in pH or pH is out of range.