Leaves curling don't understand why.

I have 4 X B52 plants and 9 Skunk plants currently flowering under a 400w HPS. They are all in grow bags with coco peat as a medium.

I have grown the exact strain on both before as they are all from the same mother. The skunk is 100% fine and shows no problems, there is about 4 to 5 weeks left on the flowering.

The 4 X B52 plants however has all the leaves curling. Curling inwards, not upwards and the leaf is not feeling crispy so I don't think it is under watering. Some are curling more than others. The plants get the same amount of water and I am pretty sure I am not overfeeding as there are zero signs of nute burn.

The b-52 plants are large and bigger than the skunk, so all I can think is that they are root bound. Could this be the cause???????

Too hard to guess without pictures. Sidewards folding and/or 'clawing' sort of sounds like too much P and/or overwatering. If you suspect that the plants are rootbound, which they probably are unless they were repotted right about the time they went into flowering, you should use a runoff tray and water and feed heavily.

Cut it with more perlite too much water.

Thanks guys.

I think I am overwatering maybe then. There is a runoff tray so they dont sit in water. I am going to water less and see what happens. Thanx a mil

**********UPDATE**************

I have been watering less and the problem seem to be stabalising. Must be that then. I have discovered I had very high humidity in the room. Sorted that out by putting the extractor fan on 24/7. Much better now. Thanks again.