Quote Originally Posted by SIDARTHA
ok. i'll go buy magnifying glass and check for trichcombs..
so what u r saying is that its not much of a problem even if the bottom part of the plant looks like a desert? and it wont recover???
Well it would depend on what stage its in, from here with no pics it is normal for leaves to yellow and die off as it is absorbed, starting from the bottom. Now if you were in veg or early flower I would say you have a nitrogen def.
Quote Originally Posted by SIDARTHA
what about co2? i'm not giving them co2 at all. just water and nutrients. is that not good?
Not sure about C02 but I wouldnt think that was your problem. Water and nutes is all they need just make sure you aren't over feeding and if they are indeed in later stages of growth then you can start to slow the Nitrogen to them as they dont require hardly any. Check your pH also.

Quote Originally Posted by SIDARTHA
does spraying water firmly make them recover by any chance? or make them healthy??
please tell me.. i'm still in need of many advices and helpful comments....!!!!
If your in flower I wouldn't because the water will have a hard time evaporating and could cause budrot or mold. Also do you have flowers? If not or if you have small flowers you could be looking at a light leak issue. Post some pictures so maybe someone else has some more ideas.