Week 4 of flower issues - CBD strain

[rick-j]

Thanks, i'm using RO water for the first time, trying to do things right. It's so easy to screw everything up soooo quickly----

 

[DTOM420]

I have had the same issue and last couple weeks of life they get ph 7 water until I see deficiency show. But most of the time they are fine up until chop.

Thanks, man! Great tip. I’m going to try that. I need to defoliate today because that Kush is so damn leafy I’m getting wet spots where the leaves are laying on each other. So, most of the leaves showing deficiency will be gone.

Is the final flush supposed to be PH 7 plain water? I have been going with 6.5, doe's that make any difference?

The pH of the water isn’t of importance in the flush. Just pH your water to what is working. Now, if you were having a soil pH problem and were flushing nutrients or trying to change the soil’s pH, THEN you’d want to flush with water that was pH’d in the direction you wanted to go. So, for example, if your soil was 5.5 and you were looking for 6.5, you could flush with 7.0 or even 7.5. That should help to raise that soil pH but it’s a stress on the plants and should only be used if you need to flush anyway. There are gentler ways to raise soil pH.

Flushing....I listened to a fascinating podcast with a cannabis researcher and consultant that says “flushing” your plant to eliminate bottled nutrients is a a waste of time and is just ‘bro science.’ I’ll post a link below. I can’t remember where she talks about it but the whole interview is fascinating! Makes sense too. I mean, think about it...plant biology has no mechanism to facilitate any “flushing” action. If something is inside the plant, it’s not leaving because you add a bunch of water. I’m no scientist and I’m probably saying it wrong so I’ll just refer you to her explanation, which really makes sense. Maybe something else is occurring when we do a “flush” but it’s not actually removing bottled nutrients from the plant. Just thought I’d share that.

 

[AutoLowRyder]

Calmag locks out under 6.2 in dirt

Not according to the Ph to nute uptake ranges, shown below;

tom420, you mention teaspoons........... it appears you have run a small nute burn episode, as you do not control your nutrient salts going in with an Ec meter................ i suspect your recent Ec is above Ec1.8 (Hanna Scale). As the last few set of upper flower leaves are showing the nute burn, and not the lower fans. So it is something you have done recently............

if you do not have an Ec meter, but do have a Ph meter,........... get a 100-200ml run off in a cup, get run off using a zero nute water Ph'ed to 6, at 23c when fed for a run off test. Check the Ph of the run off, if you have over nuted the grow medium............ the Ph of the run off will be low 5.8 or less. To rectify, feed a few less teaspoons, and Ph your feed to Ph7, you tap water, may give you this, after adding nutes, if you are on hard water, you wont need to Ph up your res water............... ensure it is 2c above root temp, which needs to be 21c minimum...... ALR

Diagnosis;
It's Nute Burn As No Ec Meter Used To Control Consistent Nute Delivery. The brown spots mid fan = nute burn.

Prescription;
Raise water temp, lower nute potency, raise soil temp, and raise Ph with B-carbonate of soda or silicon to 6.3 minimum.

 

[STILLSMOKIN]

Not according to the Ph to nute uptake ranges, shown below;
View attachment 1016954

tom420, you mention teaspoons........... it appears you have run a small nute burn episode, as you do not control your nutrient salts going in with an Ec meter................ i suspect your recent Ec is above Ec1.8 (Hanna Scale). As the last few set of upper flower leaves are showing the nute burn, and not the lower fans. So it is something you have done recently............

if you do not have an Ec meter, but do have a Ph meter,........... get a 100-200ml run off in a cup, get run off using a zero nute water Ph'ed to 6, at 23c when fed for a run off test. Check the Ph of the run off, if you have over nuted the grow medium............ the Ph of the run off will be low 5.8 or less. To rectify, feed a few less teaspoons, and Ph your feed to Ph7, you tap water, may give you this, after adding nutes, if you are on hard water, you wont need to Ph up your res water............... ensure it is 2c above root temp, which needs to be 21c minimum...... ALR

Diagnosis;
It's Nute Burn As No Ec Meter Used To Control Consistent Nute Delivery. The brown spots mid fan = nute burn.

Prescription;
Raise water temp, lower nute potency, raise soil temp, and raise Ph with B-carbonate of soda or silicon to 6.3 minimum.

Okay did you look at ca locks out in soil at 6.5

 

[AutoLowRyder]

Thanks, i'm using RO water for the first time

just wondered, what are you buffering the "RO" with ??................ before i started using "rainwater" zero Ec. I used RO, i used to add, to 20ltrs of RO 5 to 9ltrs of hard tap water, to an Ec of 0.25 to buffer the RO and prevent cal/mag deff............. i still do now, but i use rainwater instead of RO........... ALR

 

[STILLSMOKIN]

Soil ph availability chart because he is in soil, calcium and magnesium locks out same

 

[AutoLowRyder]

because he is in soil, calcium and magnesium locks out same

calcium lock out means his soil must be acidic, what would your prescription be to rectify low soil Ph ?? ALR

 

[STILLSMOKIN]

calcium lock out means his soil must be acidic, what would your prescription be to rectify low soil Ph ?? ALR

Judging by darkness of leaves, water only ph to 7 for the next few feedings. The reason behind this is all the nutes that have been put in from time of lockout is still there, just unavailable. But on chart best ph is 6.5 same as I run mine. So while hitting with seven keep an eye on runoff for ph to get to 6.5.

With it being soil 6 is way too low.

 

[Clix]

No sir. But I have a DP Auto Ultimate in the tent next to her that has very similar speckling at the leaf tips and along the margins of the leaves; and the Auto Ultimate’s oldest and biggest fan leaves, at the bottom, ARE yellowing badly. Any ideas?

Maybe @Weed Warrior has some ideas.

So IF your accurate 8 is right or at least close. Nitrogen and phosphorus can get locked up in low PH like that. Or say if your ph is on the way to that kinda of low it would lock out calcium and Magnesium first then work its way to Nitrogen and Phosphorus. I think it would be good if you can get another type of Ph test done to verify or contradict your current one. Personally I have had ph that low in coco and I saw some calmag but I saw a big hit on my nitrogen. with significant yellowing starting at the bottom of the plants.I also saw purple petioles and purple streaks on my stalks and necrosis patches that caused parts of my leaves to curl up.

Ps I had two Accurate 8 soil meters and nether worked right for me. I was growing in coco though not soil. Hope this info helps you.

 

[Waira]

:smoking: Hey Tom! I see the margin teeth showing necrosis,... mild nutes (I like HPK) and inputs so no way this is burn from organics, more likely K defc, but hold on for that a sec,..... soil pH is hard to verify now by slurry unless you wanted to dig up soil from about mid-level...... I recall the issue with your A8, figured you'd send it back? Did you ever retest the Roots soil slurry? Further digging on slurry tests, I see some use 1:1 soil/water, other 1:2,... I believe 1:1 is closer to what the roots experience because 1:2 is diluting quite a bit more which will alter pH.... You can always get an inexpensive dropper test kit like the ones used for aquariums to confirm what you pH meter says about the slurry pH.... pH meter still checks out too right?
I see no info about your T and RH%, basically the VPD is what I want a feel for,... is there high T, low RH%, lots of air movement? This type of tip/margin burn looks more like an transpiration issue, sometimes if some or all these things are off, the plant is really having to haul up the water, and with it come the nutes; boderline VPD can cause something of a localized nute build-up, and at the "teeth" there are larger than usual "pipes" leading out to the edges,.. accumulation of unused nutes, like K, can start such browning/spotting.... It's not Ca defc. either way, but keep on that with the RO water use...
...micronute input is too low mate, weekly at least,... I see some early signs of possible Zn on the pale tops, and/or these are too close to the lights.... I say that because I think i see some edge/teeth up-curling on them? get me that T and RH% info please....