Attached are pictures of the problem. I am growing in soil and the plants are about 6 weeks into veg. They have not been growing quickly because of this issue. I have not been feeding them because the soil has slow release fertilizer and i was worried that it could be a ph problem and thus adding nutrients would make the problem worse. I was desperate, so i tried adding blood and bone plant food to one of the plants and it responded well. But now its going back to the same problem. The lime green leaves and the curling and discolouration as you can see. The stems also seem weak and have trouble holding up. Does anyone look at this and think yep this is the problem? I suspect it might just be underfed but im paranoid about adding too many nutes. The pots are nice and big and so there are plenty of room for the roots and the temp in the grow room is between about 20-25 degrees with humidity of about 70%. I dont think any of these factors are the cause. I suspect the cause is simply underfed. Does anyone agree?
Foilar feeding it is for you then, years ago I had the same issue, and went the way of the spray, simply add half a teaspoon of your nute to a pint(600ml) spray bottle add warm water ...and spray 2x times per day but first flush your soils get it back to 0 ..then foilar feed to my blog: http://forum.grasscity.com/blog/1093/entry-9829-fl...
I flushed my soil and gave them a stronger nute solution than last time and they have come right. So basically i think it was just underfed with possibility of the soil ph becoming slightly more acidic from previous nute solutions. Do you really need to be concerned with ppm of your nute solution if you are doing a soil grow?