stems purpling, leaves browning!

[vek11]

My issue seems to start around week 4 to 5 Of veg! I get leaves to get what looks like a phosphorus def, and stems begin to purple! Not to sure what causes this! I'm running GH flora nova grow with kangaroots,silica blast, and super thrive. I change res once per week and my res temps stay between 68 and 71 degrees. I have no root issue but my pH does fluctuate from 5.7 to 6.1! I notice when my pH drops below 6 my girl shows signs that she docent like. All advice greatly appreciated. The strain is delicious seeds cheese candy!!!

 

[Seamaiden]

They're barely beginning to purple, and that is another sign of P-. I don't grow using that method, though, so cannot further advise. The plant looks pretty darn good to me, though.

 

[mayonnaise]

I was gonna say it looked pretty good also. I was afraid I wasn't seeing it correctly. If its deficient it looks like just a little tweek would do. Post a few more close ups of the affected area because the wide view doesn't look bad.

 

[PaperStreet]

Ill be honest i had the same issue with the cheese crosses i have ran the stems always seemed to harden off and get that reddish purp color not bad but i did notice when takeing clones. Never had any issues that i know of and i never got it figured out. Have u tried throwing a little bloom in the mix and a little calmag never hurts along the way as well. Let them ride the ph they like to ride, I have had strains push me back to 6.2 no matter what i did to keep them at 5.8, some sativa leaners just like a higher ph and lower ppm just like most indicas like a higher feed and lower ph it just is what it is. If u ph down to 5.8 and she pushes back to 6.2 dont worry its natural most of the time and she gets plenty of what she needs in the swing as well as just plain sitting at 6.2.
Id like to see a lights off pic and a close up of the stem, she looks a little underfeed honestly but that may be the lights playing trix on me.

 

[vek11]

Definitely underfed, just received my RO system so I can get dead on with feeding now!!! This is her 8 days into flower and day 1 is second pic!!!

 

[Joe Fresh]

looks to me like she needs more nutes...

 

[BakedReality]

Are you still running PH at 5.8? I am not sure I understand...if you notice the plant becomes unhappy below 6...why start her under 6? I run DWC and Tables...I ph at 6.1 with GH Flora Series. Your PH level will also dictate the absorption rates of nutes. Fluctuation is not a bad thing IMO...I welcome some fluctuation...unless it is big swings. I use Advanced PH down...for stability thru a week.

 

[vek11]

Are you still running PH at 5.8? I am not sure I understand...if you notice the plant becomes unhappy below 6...why start her under 6? I run DWC and Tables...I ph at 6.1 with GH Flora Series. Your PH level will also dictate the absorption rates of nutes. Fluctuation is not a bad thing IMO...I welcome some fluctuation...unless it is big swings. I use Advanced PH down...for stability thru a week.

I have since turned things around hydrologic RO unit, got rid of terrible water now the girls are singing. They didn't like it for 8 to 9hrs but pulled through and now all those symptoms are dissipating!