Mn deficiency?

FFOF/Perlite/dolomite 5 gal, 4 weeks veg'd under 90w, week 6 of 9 with 250w (160w high-quality CoB) in 5 square feet
H16 base (1-1-3, includes calmag), supplemented by Sea Grow + Hawaiian Bud and bloom (PK boosters), Extreme Serene/Big Bloom (organic stuff).
Feed/water every 2-3 days, first half gallon E=2.5-3... second half gallon E=1-1.5. My starting E=.2-.3
- I don't adjust pH, but it goes in between 6.0-6.5 and I add beneficials.

Jack 47 Fast (Jack/AK47 mix crossed with its own autoflower)... I did a lot to keep them extremely short and bush-like. Despite their short stature, they're healthy and I have 4-6 inches of penetration under my canopy in a very dense environment. I noticed this a few days ago and it's gotten worse... the following pictures were taken under a very small amount of 3000K light and my camera's flash.

It's worth noting that these plants were starved for five nights ending a week ago... it couldn't have been helped. My other plant faced some temporary damage from P-def, but it's fixing itself and hasn't gotten much worse. I believe it is either Mn or Mg deficiency based on the following information:
http://www.growweedeasy.com/sites/growweedeasy.com/files/manganese-info-marijuana.jpg
http://www.growweedeasy.com/sites/growweedeasy.com/files/magnesium-info-marijuana.jpg

Please help!



Bad pic, but the rest of the plant is relatively healthy with little to none of the symptoms above. It's very localized:

That does look like advancing magnesium def., which is strange because you write that you're giving some calmag. Looks like you're giving too much fert and FFOF doesn't need much. I think I'd try stopping the ferts for several days to a couple of weeks and just try a water with calmag only, or one half teaspoon in a gallon of water of Epsom salts and see what happens. Looks like you're close to finishing so maybe no more ferts, just the Epsom, and just water after that and let them finish. almost there.

I've been giving them Mg through my heavy 16 (only 1%) and Sea Grow (.5%). This actually makes complete sense... it won't be too hard to add some epsom. Day 42/55~63

Thanks

It's a combination of calcium and magnesium deficiency. You mentioned supplementing with CalMag which leads me to suspect it's rootbound.
In my experience, bushed out plants do better in a wide container or root pruning container. When a plant grows more laterally it sends out more lateral roots as well to stabilize it. If you have a standard container it may have become rootbound more easily. This is of course after ruling out all the obvious culprits.....ph, temp, ppm, toxicity, deficiency, etc.

I might be better to use a more well-rounded fert next time, something that has a lot of nutrients in it to reduce the chance of this happening.

I'd say nitro or iron your with the green vein and looking mid flower ish. What is the total NPK of your cocktail? Noted base nute is only 1 and calmAg usually carries a 2 in the n department. Do you have a liquid iron your partial to? Top dress some coffee grounds. . At this late in flower may get a partial recovery however we do put them in flower to die Lol..

Heavy 16 is two parts... Its combined NPK is 3-3-9 (divided by two). I increase my E from .5-2/2.5 and give a half gallon each to my plants. N def is somewhat hard to believe considering I used FFOF and H16 has a favorable amount of it... But it definitely resembles some iron issues.

I've added iron via my organic stuff and a little bit of it through Sea Grow. A strong dose shouldn't be too hard.

Thank you for taking a look at my plants, I'll do some research tonight.

thegreensurfer said:

It's a combination of calcium and magnesium deficiency. You mentioned supplementing with CalMag which leads me to suspect it's rootbound.
In my experience, bushed out plants do better in a wide container or root pruning container. When a plant grows more laterally it sends out more lateral roots as well to stabilize it. If you have a standard container it may have become rootbound more easily. This is of course after ruling out all the obvious culprits.....ph, temp, ppm, toxicity, deficiency, etc.

Click to expand...

I missed this earlier, thanks for taking the time, I appreciate it. They're in 5 gal smart pots... so ideally they'd be air pruned. I didn't take a picture of it and lights are off, but I've had roots showing at the bottom of my container since the beginning of switching the lights (from ground level to a few inches up, you can see them pruning).

Regarding CaMg: I added a bit of dolomite to my soil mix (probably not enough) and Heavy 16 has CaMg as part of the base nute. Said CaMg in H16 is somewhat low and I think I noticed some early Ca deficiency signs on my other plant. Hitting it with a round of micro + CaMg should get me through flower... I'll draw up a modified feeding schedule now.

Thanks guys!

No problemo. You mentioned starving her? Does that mean it didn't get any water for 5 days..... Or no nutrients for 5 days?
Fabric pots get very dry very fast and root damage can occur.

Fed Thursday night... added some plain water Friday morning. Added plain water Monday night, fed Tuesday (a week ago). Night and day are flipped for my plants, so night is morning and morning is night. 84 hours without water and 120 hours without food after being fed every 48 hours (sometimes 72), consistently.

I have either damaged the roots (plant has actually slowed down drinking by a little bit), have CaMg and/or Fe problems, or have K tox (which can lock out Ca,Mg,Fe).

Other plant has shown a bit of the same problem, yet it's drinking a lot and a few of the roots at the bottom of the pot look healthy. I'm really sold on K tox and the answer to fix the deficiencies is the same as K tox... I'll lower my base nute and add some CaMg & micro.

Edit: To further explain, H16 has a 1-1-3 ratio and my P-K booster is 4-26-26, so it's developed into a lot of potassium. Hence, I should have been aware this might be an issue.

Have you looked into autopots?

I have not... I've considered blumats though. Thank you for pointing me in this direction.

You probably don't need to add much in FFOF.
Did you try the Epsom salts yet and if so, what has been the outcome?

I added about 25-30mL of OilyCann (3% Ca, 1% Mg) to each of my plants, as it's what I had on hand (old bad purchase). This took the place of my base nute (1-1-3) in my feed as I'm trying to attack the potential of K tox as well. Chopping in 2-3 weeks, I should be able to keep them healthy enough until then as it's spreading extremely slowly. The plant is dying, I'll only be able to do so much at this point.

Comparison, two nights ago (left) vs tonight (right):


Too early to tell. It's gotten a little worse, but I just fed yesterday. My left plant (Sativa dominant) is starting to develop some of the same symptoms, with chlorotic spots turning into rust.

why are you convinced there is K tox?
25 ml sounds like a lot, meaning too much.

My base nute is high in K (1-1-3 ratio) and until a week or so ago I was giving it a supplemental P-K booster that had equal amounts of P and K. Add this on to the fact that I'm seeing a bunch of Calcium and Magnesium deficiencies, even though I mixed and top dressed a ton of dolomite, I just have a hard time believing this is deficient. So K tox or maybe even a low pH. My plants are due for a pure watering, I'll water slowly and see what my runoff pH is... I've kind of been taking for granted the fact that I'm using soil and adding beneficials, but a low pH is an issue with FFOF.

Yeah it was a lot... but it's a one time shot with a pure watering coming up next.

NPK ratio out, too much K will cause nute lock out issues, they need more light to make em fat not more K