OMG My babies! Please help....cal/mag?

[NotMeYou]

I just noticed the tops of my plants have yellow leaves in some spots with cal/mag deficiency looking spots?

I know what cal/mag deficiency spots look like, but almost the whole leaf is yellow on some of the tops. (I did lower the light about 7 days ago, but it's still 18-24" away from the tops and not all of the leaves show the symptoms, so didn't think it was heat related).

New to growing, so any advice would be appreciated. (I have read everything backwards and forwards, so have the basics in terms of "booksmarts")

Details:
Coco in 1 Gallon or larger containers
Canna Coco A&B nutrients with Rhizotonic and Koolbloom now as primary feeding
1800 ppms...(plants are about 2 or 3 feet tall)
28 days into flowering under 1000HPS with some extra CFL's thrown in
6x6x6 grow tent
Huge fan blowing all the time in the room, but humidity is still up there at times
I did give them cal/mag a week ago in their feeding nutes when I saw the little brown dots starting, but maybe it was too little of a bump.
PH is always set at 6.0 on the way in with nutrient mixture
Temps are usually right around 80-90 (at night fan stays on and heater in room keeps it around 70 degrees, but I'm changing it to 75 I think)
Co2 is pumped into the tent, but I'm sure there are holes, so call it "light" Co2.

Using tap water, but I have not had any issues previously or with my hydro setup, so I think that it is something else. (48 ppm out of my tap...crazy good water around here)

I REALLY don't want to do a flush if I can avoid it. The setup right now makes that very difficult. (I understand PH'd water at 3x medium size for flushing)

Thanks so much for your help, I'm an authorized medical patient and it would suck to have to go back to the "old" ways to get my meds!

The pics are hard to get to come out right, but take a peek and tell me what you think. The last two show the yellow leaves better, but the HPS light was on, so not sure what that does to the colors...doh!

 

[EvilTwin]

NMY,
A common problem with new coco growers is not preparing the coco properly. More important with bricks then with the bagged coco. What brand and what preperation did it get?

And also, Ca and Mg are two different nutrients and deficiency issues for each are different. Even though they sometimes occur together. The brown spots certainly could be calcium related and the yellowing leaves are more likely N related.

The calmag you added should be continued for a week. That's about how long it takes to correct either deficiency.

Doing such an unscientific CO2 administration could be risky. I've never used it, but I know too much can cause problems.

Sorry I don't have much to offer but at least your thread got bumped...
ET

 

[Moldy Dreads]

I agree with eviltwin, but I also have experienced many grows where only one genetic showed that deficiency or similar ones even though mediums and every thing else where the same. I believe some plants just are more susceptible or are more sensitive to certain nutrients and mixes more than other strains..

 

[EvilTwin]

I agree with eviltwin, but I also have experienced many grows where only one genetic showed that deficiency or similar ones even though mediums and every thing else where the same. I believe some plants just are more susceptible or are more sensitive to certain nutrients and mixes more than other strains..

Hey Moldy!
That's so true. I have a dozen plants in bloom right now and one (different strain) is all covered with brown spots while the rest of them are perfect. Solution: Scrap the genetics and move on.
Peace,
ET

 

[NotMeYou]

botanicare coco

botanicare coco

I used botanicare coco which I used last time (my first time) and did everything the same with the same strains I'm using now and never had an issue at all.

I flushed it before using it (even though it said you don't have to) because I read better safe than sorry on the boards here.

I used a very light PH'd nutrient mix to flush and they were fine for the month they veg'd and it is only coming out now during flowering.

Things that have changed since vegging that may be the issue:
Bigger Plants
1000 HPS light now vs LED, Floro, CFL while vegging
Added KoolBloom to nutrient mix
Upped PPM's (would too high of PPM cause Yellow leaves?)

That's about it. I can't think of anything else that has changed since Canna nutes are used throughout veg and flower.

It seems to be only towards the top, so I think maybe heat is the issue. The light is pretty far away (almost 2 feet), but the tent itself gets hotter than they were used to in the veg tent, so maybe the extra heat from the light which normally wouldn't be an issue is causing the issue with the added heat in the room?

I just didn't see these symptoms as caused by heat issues, so don't think that's the issue.

Maybe too many nutes creating a lockout of N or cal or mag?

Thanks for your advice so far though!!!

Anyone else have any ideas? I'm close to massive flush, but that will be suuuuuuuch a paaaaaain, so really grasping at straws before I bite the flush bullet.

 

[EvilTwin]

NMY,
Yes, excess ppm (nutrients) can cause a lockout of other nutrients. Your nute level does seem a little high.

Your coco regimen seems ok. I don't see that there's any light burn (bleaching) going on...but the heat in the tent might be an issue. any way to reduce it?
ET

 

[NotMeYou]

fixing issues...

fixing issues...

Okay, I see that the huge fan I have in the tent was on the low setting, so I put it on the high setting and aimed it at the wall of the tent. It makes a HUGE difference in temp in the tent and also should lower the humidity which seems a little high to me (using my spidey sense only though).

I flushed the one gallon bots with PH'd to 6.00 water with 1 teaspoon of cal/mag (just cuz I know they like it). I could only do 2 gallons through each pot though because that is all of the water I had ready (as in sitting out 24 hours).

Going to see how they look for the next two days. If they seem to be holding steady with just the current ruined leaves, then I will nudge the nutes to half strength and leave out the koolbloom and put cal/mag in its place for the next week or so.

Will keep you posted, but let me know if you think of anything else.

It appears to be only the top leaves...Fan leaves and a few of the little ones out of the top cola too. The worst fan leaves have turned all yellow except for little dead spots. I feel like the dead spots are just a cal/mag deficiency and so didn't turn yellow the way the rest of the leaf did.

I do see some that are starting to get yellow around the outside of the leave while the middle of the leaf is still green. I will yank a couple and take pictures tomorrow and post them.

I think I over nuted since the leaves are turning down at the tips a bit too. Isn't that a symptom?

Thanks for your help!!!

 

[B.C.]

Flowering plants will use more water than vegging plants will because of the higher rate of transpiration. Keep the coco moist, it tends to lock out Cal if you don't. Good luck! BC

 

[NotMeYou]

Pics of leaves

Pics of leaves

Here are some pics of a leaf I took off.

Again, just the top fan leaves on a few different "arms" of each plant. Also some of the sugar leaves barely show it on some plants.

This pic shows that it is more of a very light green than yellow as I previously thought (stupid HPS lighting!).

After this stage in the pic, the leaves get really dry and break if I bend them and pretty much die.

The newest leaves I saw it starting on appear to be starting at the outside and working in towards the center of the leaf with the lightening color.

Bottom leaves all look fine.

Any new ideas? Thanks!!

 

[Moldy Dreads]

Any new ideas? Thanks!!

Solution: Scrap the genetics and move on.

or change the medium up with that plant next time to see if it likes it better...

 

[ToughGirl]

Looks like a fungus or a form of blight. Some strains have better immune systems than others. Btw, there is a problem with blight this year, brought on by low temps and high humidity. Try a different strain (indica if possible) and see how it goes. Every time I see this on a thread, everyone thinks it's a Mag deficiency, but cal/mag or epsom salts doesn't fix it.

 

[psycho pirate]

Looks like a fungus or a form of blight. Some strains have better immune systems than others. Btw, there is a problem with blight this year, brought on by low temps and high humidity. Try a different strain (indica if possible) and see how it goes. Every time I see this on a thread, everyone thinks it's a Mag deficiency, but cal/mag or epsom salts doesn't fix it.

yeah you are definately right about ca/mag def being the most misdiagnosed problem in these forums... I find most of the time it tends to be something wrong with the pH and/or some kind of salt toxicity build up. Adding more nutes before you know what the problem really is can cause more problems than it fixes. Try using humic and fulvic acids to buffer pH and help with plant stress.

 

[xmobotx]

that's potassium deficiency - meaning it must be a lockout since you are using coco

w/ the brown spots and necrosis at the tips, it's toxicity

you have to flush.

Your prob is an excess of K not balanced out

feed very weak after flush avoid potassium use some cal mag

 

[B.C.]

hmm...

hmm...

I dunno guys, I think if it were fungus, blight, PH, salt toxcitity, or even the genetics of the plant itself, it would be covering the whole plant. Look at the first pictures, the bottom is lush green and happy. So whatever it is has started not too long ago.

MTF Sandman once posted info on a situation jus like this. He went into detail as to why letting coco dry out too much would lockout cal. I'm sorry I don't remember those details. lol Just that it would do it, some strains more than other too, I believe.

Anyhoo, my line of reasoning is that this plant is right in the middle of flower. At this point she's transpiring at her peak, almost twice as much as it did in veg. Which means it's going ta need to be watered almost twice as much to keep up with it. If not, the coco is going ta get very dry and lock the cal.

This would account for these symptoms not showing up till now. I reckon it would be easy enough to tell, keep em moist all the time and see if it stops spreading.... Those are my thoughts anyway. lol Hope it helps. Good luck! BC

 

[norcalkell]

cal/mag def

 

[cornflake]

I grew in coco for 10 years around 20 years ago. I stopped smoking and growing for 7 and lost my skills. I'm not a coco expert or anything, just illustrating that I have seen different things.

I'm growing in coco again, for the past 3 years and I have seen those types of probs but never all at once

I let my coco almost dry out before every watering. I never feed unless nearly dry and I never see lockout due to that.

I've seen it caused by overfeeding and pH out of range.

Check your pH (you probably already have, sorry am not reading whole thread).
Check your pH measurement is accurate. Get drops, a tape kit to back up your electronic tester.

As people have already said, you need to feed lighter not what yu think it should be getting at this stage of growth. Fix the problem first.

How do you measure pH? Is it calibrated and checked properly?

 

[Phillthy]

i see it from time to time in soil. i let the leaves dry and fall off and it doesnt seem to affect bud production at all. plants still produce killer smoke. some plants will display it while others of the same strain do not. this is definitely a deficiency and not toxicity. flushing will usually make it worse.

 

[NotMeYou]

meter is accurate

meter is accurate

I had already calibrated my meter.

I think it was over nuting....maybe with a shot of overwatering too.

I was watering 3 times per week and going with about 1800 ppm and I don't think they were liking it too much.

Will keep you posted. they are all dry now and I'm going to do a light nute with a little cal/mag and keep it around 1000 ppm or less and see how it goes.

Does seem like the buds keep growing, but I have to think I have stunted them a bit since it wasn't a perfectly smooth growth session.

doh!!!

thanks everyone and I will make sure and update you for your own records and so you know if you were right or what with your recommendations. More knowledge = good!!