Leaves Curling Up... Any idea why?

A few of my indoor plants are showing signs of this curling. Most of them are in coco, but a few are in soil. Does anyone know what this indicates? The temp and humidity are at correct levels. They are in the veg stage.

Without a picture its hard to say, (2years exper.)
A good rule that I follow, many windbags that post will probably disagree, if it curls up its to full of something. If it curls down its empty.
This is not true in every case, thats where I start my search for problems. Yours are curling up, if the tips are drying I would say nitrogen burn. If the tips are fine but curled up I would look at the other nutes. My exp I can not say for sure.

Sry, didnt see pic. it looks like one of the other nutes are to high. I cannot help in that area.

Heat stress/Over-Underwatering? Feeding schedual,nutes N-P-K. Pot size?
What is your Humidity? Fans/ Airflow?
What kind of light? How far are your lights? etc...

Lets not forget about what is your ph?

I'm going to lower the pH in the next 2 feedings and see if it helps. Might be too high pH. It was around 6.5.

Heat stress/Over-Underwatering? - not too much heat, but I haven't been overflowing the watering (at least not much)... think that could do it?
Feeding schedual,nutes N-P-K. Pot size? - once per day... 6 are in Coco and getting COGR nutes, Cal/Mag (to aid city water), and Rhizotonic all in quart pots. Plus, 2 have it in 5 gallon pots with soil, Terra Vega and Cal/Mag.
What is your Humidity? Fans/ Airflow? - 45-55%, Yes
What kind of light? How far are your lights? etc... - Compact fluorescent, just right

Thx.

How far away are your lights? Mine were too close and started undercurling leaves with no damage. I raised lights and started occasional misting of leaves and this stopped. Try more ventilation to carry away heat and if possible raise light. I was in a very height restrictive area when this occured. I moved to a 10X15 room and everything is looking great. A curl with a burning tip "IN MY OPINION) is a nutrient issue, too much. I look at curling drying tips as a burn. Someone ridiculed me for saying that a persons plant was burning its leaves because the tips and other full leaves were burning, they told the person not to listen to me but feed the plants more nutrients, If you find drying out tips you can guarrentee that the nutes are burning, when this happens to me I flush and wait a few watering cycles to nute again. CLEARS RIGHT UP...
I have grown for two years and this year is my best crop. First crops are ALWAYS experimentals sop remember that everyone.