problem: yellow leaves, purple stems

[Izzy180]

Sorry if I put this in the wrong place..

"Problem: yellow leaves, purple stems
Medium: Pro HP coco
Feed: Mephisto genetics super soil amendment
Strain: Mephisto Genetics White stomper & freebee from MG
Climate: day max 81°/ 72°min night, relative humidity 50-60, light used Mars Reflector 144, number of plants 2 , how you vent 6" hyper fan
Additional info: How long have the plants been affected? 1.5 weeks - Have you had the problem before? yes
Anything else you think might be relevant..Need some help guys. I thought I had taken care of this issue buts its returning. First time grower...... Thanks in advance...

 

[Waira]

Izzy- this is looking like a P defc. issue,.. I'm familiar with the set-up using that supersoil mix too,... either the P source is tapped out, or the soil pH is off enough to start locking out the P, meaning the P is there, but is rendered unavailable due the chemistry changes that off-pH brings,... get me a whole plant pic, that might help,.. it's looks like just P, no other symptoms, which hints that it's a simple lack-of type defc., which would be good news and easy to fix! Only way to tell is to get a soil pH though, and if you don't have a pH probe, then you have to do a run-off test.. not really recommended with this set-up because it'll require a saturation of the soil,.. you have a pH meter though, right? Calibrated recently..? get me that whole plant pic please, and we'll see,....

 

[Izzy180]

Izzy- this is looking like a P defc. issue,.. I'm familiar with the set-up using that supersoil mix too,... either the P source is tapped out, or the soil pH is off enough to start locking out the P, meaning the P is there, but is rendered unavailable due the chemistry changes that off-pH brings,... get me a whole plant pic, that might help,.. it's looks like just P, no other symptoms, which hints that it's a simple lack-of type defc., which would be good news and easy to fix! Only way to tell is to get a soil pH though, and if you don't have a pH probe, then you have to do a run-off test.. not really recommended with this set-up because it'll require a saturation of the soil,.. you have a pH meter though, right? Calibrated recently..? get me that whole plant pic please, and we'll see,....

I will get you a pic first thing & thank you for your help. I do have probe but it's Very and is not calibrated. I do have a regular PH meter though. I forgot to add. I was supplementing with 2ml growswitch full on and 5ml cal mag per gallon for almost every feeding.

 

[Izzy180]

I have other pictures on my grow thread. Kinda new here so not sure how to link the thread. Sorry

 

[Izzy180]

Izzy- this is looking like a P defc. issue,.. I'm familiar with the set-up using that supersoil mix too,... either the P source is tapped out, or the soil pH is off enough to start locking out the P, meaning the P is there, but is rendered unavailable due the chemistry changes that off-pH brings,... get me a whole plant pic, that might help,.. it's looks like just P, no other symptoms, which hints that it's a simple lack-of type defc., which would be good news and easy to fix! Only way to tell is to get a soil pH though, and if you don't have a pH probe, then you have to do a run-off test.. not really recommended with this set-up because it'll require a saturation of the soil,.. you have a pH meter though, right? Calibrated recently..? get me that whole plant pic please, and we'll see,....

My soil PH is at around 6.8 I guess it need to be lowered right.

 

[Izzy180]

Pics from this morning. Just watered yesterday morning with RO water,5ml cal mag, 1/2 tsp molasses, 1ml liquid cool bloom @5.9. I didn't get that first message in time. I gave them each half gallon of plain RO water @ 5.49ph this morning.

 

[Waira]

..how did you take the soil pH? pH probes don't need calibration, at least not the bi-metal tip types,... the skinny cheapo ones you see at garden centers are lousy for accuracy,..only one of this type I trust is the Accurate 8 (Control Wizard) hsoil:<- this long probe one here is the A8,... the accuracy of your soil pH reading is critical here, for reasons stated above...
..are you using a Ca-Mg supplement? RO water has none, and it might be that more than one thing is depleted in the soil now, and RO is impossible to make stable with any pH'ing because those buffering minerals are gone,... even small inputs will cause big swings... also, micronutrients like Zn, Fe, Mn, B, Cu, Mo play important roles in how other nute elements are used,.... That said, new pics still look like P defc. mostly, maybe some Ca defc. too? Hard to say in that light,... You used GH Kool Bloom 0-10-10?

 

[Izzy180]

Would you recommend that I switch to tap water or just plain store bought filtered water? I used a probe to check the soil, it was an old probe from probably 1980 something lol. I will order up that soil ph meter. Yes GH kool bloom and yes I do sup with cal mag 5ml @ each watering. I just sprouted another bean 14days ago. I'm gonna try and run this next one with tap water and chemical nutes, no super soil..

 

[Izzy180]

@Waira here are some more pictures with different light

 

[Izzy180]

@Waira I appreciate your help with this... So sorry for the lack of updates.... grow [HASHTAG]#1[/HASHTAG] complete... weak grow overall I think.. only got 73 grams off of both pants. My PH issues cost me a lot I guess. Bought an accurate 8 PH Meter to test soil. I could not get it under 6.8 PH in my Coco medium. not sure if my water PH meter is fucked. Does anyone know of an east way to test my Meter... its just a cheapo yellow meter off of amazon... Can I use The accurate 8 in water? I have started another run which is almost at 40 days and is showing signs of the same issues. purple stems, in-between veins getting yellow, most inner growth is very light yellow.. I switched to tap water from this grow and I'm using synthetic nutes GH 3 part, cal-mag, kool bloom, molasses. The leaves are showing as if there are yellow veins all over the leaves.... I'm so lost please help