Is this normal?

[Jayman1971]

Hi all!
First time grower, first time poster. I have been following the recommendations on this website to a T and everything has been going really well. My two plants have been happy and healthy through the entire grow—until now. I just noticed the leaves on one plant are turning splotchy yellow/brown. This seems to be coming on pretty fast. It seems to be mainly on the mid-level leaves. I am growing in coco and perlite, using GH Flora Trio and CaliMagic going by the custom chart on this site. I’m on week seven after the flip and I know it’s normal for leaves to start changing late in flower, but this doesn’t seem quite right.
I’m in a 4.6’ x 2.3’ tent with three Spider Farmer SF1000 lights. Daytime temps are around 75, nighttime around 68. Humidity stays right at 45%. The affected plant (on the right) is a feminized Grape Ape. The other plant in the tent is a Larry OG and is doing just fine.
Any help is appreciated in advance.

[Ckbrew]

Have you consulted the plant problems page on GWE? Two big things with coco/p, calmag and pH. Coco needs to be saturated with calmag at the start no matter what the seller says about their product. I start with 10ml/gallon for the first wet down of the coco, then 5ml/gallon for 2 weeks, then 2.5ml thereafter unless they want more. Damage from low calcium will not reverse, but it will halt further progression. What is the pH of the solution going in, are you checking it? I target 5.8. Many people like pH meters, I do not. Imo pH papers are the way to go. accurate enough for growing, no calibration needed, no storage environment needs. If it is just one different plant strain and everything else is the same, you are seeing genetic differences. But take it as a warning about the other plants. I think they are to young to be starting the fade. That is your first grow? Doing very well.

[Jayman1971]

I’ve been feeding with nutes and 5 ml Calimagic per gallon every day. I let the ph drift up and down by .2 every day between 5.6 and 6.4. I use a new pen I calibrated about three weeks ago. I have a GH ph test kit I could try, but it doesn’t seem very precise. Does it look like a calcium or magnesium problem? I tried to use the diagnostics on here, but couldn’t find symptoms that match what I’m seeing.

[dirtymike]

looks like you rustled the leaves a bit and uncovered leaves that were shaded by others.

[Jayman1971]

I did do that. I clipped a few fan leaves above them as well. Nothing to worry about other than to not do it again maybe?

[changeofpace2014]

Buffering or not would not be an issue at this point in the grow - It would be for seedlings. I to grow in coco with GH / FT - I set the ph to 6.1 or 6.2 this gives a few days of drift before I need to re up the solution.

Many here check the run off as well, sorry I do not, maybe if things got bad. It might be a good place for you to start.

You could flush them and fresh solution back in. You might want to back off EC a bit from what your were feeding them prior to flushing. They look pretty healthy and would dry out quick.

[Bluey]

Welcome.

Great looking grow. Well done.

Your issue looks typical of the start of a calcium def to me and here's how I'd handle it. Warning. I could be wrong because I've chased my tail with this on my sativas.

You look like you have picked it up quite early too. Nice one.

Calcium deficiency typically low pH in the medium and/or too high potassium.

I'd give it a flush with a pH of 6.3 and a calmag sup mixed in to the effected plant. Dont add potassium supps to the flush. I'd raise the lower pH reading you are feeding them at this stage to 5.9 at least since you're in coco. I wouldn't go below 5.8 at any stage unless something went haywire and the medium ended up being very high pH for some reason.

I'd also reassess your fertigation and runoff , your watering practices. Its hard to go too wrong in coco but its worth thinking about.

Keep us informed what you do and how it progresses.

Edit. I just read Pace's post above re EC, nute strength. I use an EC meter and have no idea what teaspoons/gallon gives as a measure of EC, but too high EC could well be contributing.

I reduce lighting also to slow the problem. Too intense LEDs may contribute to this as it may be a problem I've encountered a few times.

[Gingerbeard]

Everything in the lineup sounds right. All the correct nutrients and numbers and whatnot.
I'm looking at leaves next to tent walls in a seriously bushy tent with only one fan. Could this be biological rather than nutritional? Not WPM. Not rust. Probably not septoria.
Of course, I have to throw in late-stage flowering lockout.

[Jayman1971]

Thanks everyone for all your input. It’s all very valuable and I think going by it I may have figured the first thing to try. Bluey suggested it might be calcium deficiency so I studied up on it over on the website and think that may be it for several reasons. First is that I’ve been on the lower end swing of ph lately, which apparently inhibits calcium uptake. Second, the issue is mainly on mid-level leaves that are directly under the light, which is what the website predicts will happen with calcium deficiency. So my next step, I think, will be to water and feed as normal, but with a ph of about 6.3 for a few days with full doses of CaliMagic.
Gingerbeard I agree my plants are super bushy compared to what I’ve seen others grow and that that’s not necessarily a good thing. I should have been a little more careful. I lst’d and scrogged until the tent was full and then let them stretch. I didn’t defoliate at all since I really had no idea how the plant would grow and Nebula suggested a first time grower should maybe limit defoliation until they know better how the plant would grow. In hindsight, I should have defoliated a little more at least, but by the time I came to this realization, I was too far along in flower and I was told any more defoliation would stress the plants. The only benefit I guess now though is that although several leaves are having issues, there are plenty more the plant can draw from. I’ve been trying to clip a fan leaf here and there to get light to some of the lower bud sites, but again, I don’t want to stress the plants at this stage. However, there are a lot of buds getting very little light. These are the first live pot plants I’ve ever seen, so I’m wide open to advice on any level about any aspect. I do have a fan on fairly high oscillating beneath the canopy and the exhaust fan is turned up pretty high, but you are definitely correct that the bushiness of the plant causes a serious lack of breeze between the upper and lower canopy. Any advice?
Again, thanks everyone!

[Bluey]

I'd pluck and fold all leaves blocking light to the high mid to top buds.

But do your best to get them into the light before plucking. Thats what I do anyway.

We all approach this a little differently.

Careful of calmag. Too much later in flower can be really bad. I stop week 3 of flower at the latest.

[Smallgrow]

Some brands of cal/mag can have a hit of N if I’m not mistaken , not what you want at later flower.
Plus plants are already super green and lush already

[Gingerbeard]

Another Hmm... moment Smallgrow . Mine has 2 N. Got to thinking about getting leaves that look N-toxic come flowering time. Never during veg. Dark, shiny. A bit of edge cupping. Harvest is nigh and the largest remining fans are waxy, dull, dark, and brittle as hell. Almost dry on the vine, so to speak.

[Bluey]

A lot depends on the NPK ratios of course. Ginge is giving very very low dose calmag in flower. There are very few liquid calmags on the market that don't contain N and then lucking they are compatible with your base nutes & other supps you are using regarding stabiity and integrity of the nutrients is a long shot if you mix brands. I tried a few approaches and ended up sticking with a calmag with N and just managing it accordingly. It's not the approach I wanted because I was really struggling with leaf issues 4 weeks or so into flower with my sativas showing cal & then mag deficiencies, leaves losing pigment big time and covered in the rust spots all over and drying out.

[Gingerbeard]

It's not that untrimmed, bushy plants are bad. It's the environment they are in that can be an issue. Dense canopies can block light and inhibit bud growth, but those will not kill your plant. Ventilation and circulation are important in stopping bugs and other biologicals that will kill your plant.
Like Bluey said, you got some fine looking first timer dope. Don't be afraid of defoliation. There is a whole genre of people who swear by stressing their plants.
Can't wait to see your next one!

[Bluey]

Defol can also assist if you are having problems with high humidity.

[Gingerbeard]

For you, Bluey
"There is a principle which is a bar against all information, which is proof against all arguments, and which cannot fail to keep a man in everlasting ignorance—that principle is contempt prior to investigation." —Herbert Spencer

[Bluey]

Oh. Getting learned by The Minge.

Where's my quote book?

[Gingerbeard]

Something I read a long time ago that I do not remember often enough.

[Smallgrow]

First grow, first time seeing a plant! you’re killing it.
Just keep it up

[Jayman1971]

Thanks! I felt I was getting very lucky, but that the bottom could drop any minute and spoil three months of work. I guess that drama is just the toll for growing my own weed. Hopefully after I get a few grows under my belt, it won’t be quite so nerve wracking.

[Jayman1971]

Update: problem still seems to be getting worse, but maybe I’ve cracked it. It definitely looks like the calcium deficiency symptoms over on the website (thanks Bluey), so I’ve been feeding with a ph about 6.3-6.4, but I didn’t check the runoff until today. It was 5.9, which is apparently too low for calcium uptake. I flushed it tonight with ph 6.35 and got the runoff up to 6.2. I’ll give an extra heavy feed tomorrow and make sure the coco ph stays up. I also turned the light down a little.
The confusing thing is that the runoff from the healthy plant was 6.15 (compared to 5.9 from the unhealthy plant). Everything is identical with the two plants as far a growing medium and feed, but they are different strains. What are the roots in the unhealthy plant doing that causes the ph to drop that the roots in the healthy plant aren’t doing? And I feed both from the same batch in the same sprayer, so I know I couldn’t have made a mistake with one and not the other.

[Bluey]

There is an exchange of ions at the roots which fundamentally changes the pH of the runoff. I don't measure runoff pH because it's not a reliable indicator of pH issues. I tried that on perfectly healthy plants in coco a few times and was getting really low readings indicating I had a low pH problem, but I didn't. Plants were fine.

[Jayman1971]

I’d never checked the runoff either, but I hope in this case the low ph runoff does point to a problem. The issue is getting worse and if it’s not calcium deficiency caused by low root ph, I have no idea what it could be.