possibly a combination of things?

[pseudostelariae]

whats up everyone? here i have a dp master kush about to go into flowering but i would like to get this problem sorted out before they make the switch. i looked around the site for awhile but couldn't find any pictures similar to this except maybe a magnesium issue..does anyone recognize this?
the problem started midway up the plant and looks to be progressing both up and down.
the plant is in a mix of 1/3 peat moss, 1/3 worm castings, 1/3 chunky perlite and i give it nothing but RO water.
the first picture shows the more severely affected leaf

and this is what is beginning on other leaves

 

[moonymonkey]

how long has it been that way? ever had this problem before using that medium and water? wats soil and water ph? need more info,on the grow?wat are u feeding it,at wat dose how often?,wat size pot? etc...?cant see the stems are they purple?....mooon/

 

[pseudostelariae]

how long has it been that way? ever had this problem before using that medium and water? wats soil and water ph? need more info,on the grow?wat are u feeding it,at wat dose how often?,wat size pot? etc...?cant see the stems are they purple?....mooon/

thanks for the reply. it's been progressing for 3 days now. i've never used this medium before, i am actually using it because i was told it buffer its own pH..about 2 weeks ago i transplanted from a medium sized peat-pot into a 1 gallon pot, and i plan to transplant into a 3 gallon pot to flower. i'm sorry i can't provide the pH of the soil or water, tomorrow i will buy a chemical test kit and find out. i haven't fed the plant anything yet...just RO water. also, the stems of the fan leaves are purple but the branches themselves are green. thanks for the help!

 

[moonymonkey]

did the problem start after u transplanted? or was it happening before that? from ur mix sounds lik it needs to be feed,just want to check if there any under laying problem before that? it cudvery well buffer the ph for all i know,dependin on wat u feed it an at wat dose,at wat ph..and size of pots...as far as buffering,id always check it...but thats just me...

 

[rckymtnthuglife]

Hey man you really should add dolemite lime to that mix at 2tbs per gal. If those plants are ready to flower they are probably hungry. Looks like you have some sort of pH or lockout issue. Not sure.

Not sure what size pots they are in. If they are in 1-3gal pots I would put them in the mix you are using with the added lime and transplant into 5 gal. buckets. In fact now would be a good time to add 2tbs per gal of some High P guano and 1/2 tbs kelp powder per gal as well...either or both will certainly help...and would mean you could continue to use plain r/o water for awhile longer.

If they are in 5 gal pots already...I would go apeshit and put two of them in an 18gal rubbermaid and would add 3tbs of lime per gal.

Keep them in veg and let them recover for a few days after they start to pick up...with a transplant,guano,kelp, and lime in your soil mix your plants will be thriving again within a week.

 

[moonymonkey]

i lik a balanced diet.