Small prob in big grow, first hand experience please

[20kw dreams]

I just found a prob.

I'm using the AN 2+ line in coco, but instead of using Monkey Juice, I had to use SensiAB+Cal-Mg because I guess there was some kind of a prob with the batch of MJ. It's only on a few fan leaves, right under the lights, but it doesn't look like a heat stress prob, more like a Mg/something deficiency, but I'm not seeing Mg deficiency since there is a shitton of Mg is Big Bud. I didn't however add the Cal-Mg to the Sensi A+B, so it very well could be. I'm thinking just the leaves under the light cause they're working harder, hence using more nutrients? If you notice though, another reason I'm leaning away from Mg, is that there isn't any chlorosis before the necrosis, it's like little necrotic patches are just appearing out of nowhere.

I did put CO2 in the room 4 days ago, so temps have been up a bit. Temps have been set to cool at 85F, with circulating fans everywhere blowing on everything. There was a couple of short times, for like 10 minutes or so, that the circ fans got turned off while I was rearranging cords and what not.

Basically, I can safely nail it to either some kind of heat stress, nutrient def, most likely Mg, or maybe an MG def brought on by slightly excessive heat? It makes sense since I didn't use the Cal-Mg additive and I'm in coco, eh?

I don't know, take a look. Just wanted to see what ya'll thought













And here's a few pics of the room to provide some background:smile:

 

[testpilot]

I'm running a similar setup. Air cooled 1800W over an AeroFlo style table 4x8 feet. GH Flora (lucas) and CalMag+.

I ran into the beginnings of both calcium and mag defs first week of flower. Got rusty spots similar to yours on the edges of the larger fans (calcium def). I upped the calmag+ to 6ml/gal and the problem stopped progressing. The Mg def took a few days to correct.

I ran into some heat stress problems also and I don't think that's what you're seeing. At 85F air temps, it would probably be localized to the tops only. Where are you seeing this problem start? Those look like mid-lower fans that you showed. 85F with CO2 is really not that bad at all. The first thing I noticed with heat stress was the edges curling, which I don't see on yours.

 

[AmishFarmer]

I have a similar problem.I didn't think it was a nutrient problem because where a problem leaf touched another plant it spread.Then I saw this thread http://www.icmag.com/ic/showthread.php?t=70465 Check it out,I think that is your problem too.I turned the AC back on and it stopped spreading.

 

[20kw dreams]

Testpilot - Yeah, I have some of the classic leaf curl, but it's only on a few leaves, and that is obviously heat stress. I've had alot of straight heat stress and light burn, and this is definately not directly that, which is why I think it is nutrient, but due to the location of it only being directly under the lights, I just think it is brought on by the high light. This is on the upper largest fan leaves that are getting direct light, but there are leaves 6" closer to the light that have no signs of this at all.

AmishFarmer - Good call, and worth a shit, but I don't think it is bacterial or fungus, and it's def not virus. I've seen virus's in herb, and in fact I have one now on my AK, and I could spot it in a minute. Bacteria' and fungal infections would not be restricted to interveinial regions of the leaf, and would have a more "bullseye" look to them, causing chlorosis before necrosis, as the infection attacks the leaf. I thought about this one as well before I posted, and ruled it out upon close examination of the leaf.

 

[Core]

i'm just venting my thoughts here...but it seems like the spots have burns on the sides of the spots if you look at a closeup...could it be you went overboard with the nutrients and additives?...that seems the most logical 2 me when i see that damage.. if it woz a mag def it would all be light green between the vains... just chiming in my friend ..

 

[toohighmf]

are you running in RW?

are you running in RW?

If you are growing in rockwool (which is what i think I see, and use myself)I strongly recommend you stop using the bennies
like Piranha & tarantula. the anti caking agents and a few mistakes at the bottling/packaging plant make P&T very difficult to use in rockwool, as the anti caking agents turn to a silty powder that actually clog the pores of rockwool. I have seen batches of Piranha with Heavy Harvest Nitrogen pellets in it as well.
A few shots of H202 and a rez change will kill that crap. I just hope you can flush the anti caking agents out of the medium. I think you will find Botanicares hydroguard to have the same trichoderma in a much more refined product that wont mess with your medium if you are absolutely stuck on bennies. otherwise its H2o2 all the way through for me. instead of using preventives to deal with problems, you might want to go full hydro and stop the production of live microorganisms. they have their place in growing, but not in true hydro. just my .o2.

 

[Blackvelvet]

Ph is important...are you adjusting the ph of your fert water after adding everything?

 

[20kw dreams]

Core - That's what I was thinking to with the lack of chlorosis. The slight burn is possible, I was actually thinking of diluting the reservoir before I add some Ca+Mg, that way I take care of it either way. I have ran this Sour D with the same nutrient regime, but I didn't reduce the EC when the CO2 came on, which is the only difference between now and then.

TooHigh - No, it's coco, and I only innoculated 2 x last time 2 weeks ago. I've had some bouts with pythium in prior systems, and IMO beneficials are WAY better then H2O2, but that was in mediumless. H2O2 has always seemed like fighting an uphill battle when you get root probs, but beneficials maintain a healthy biological ecosystem which resists pathogens in the first place. I have heard that rockwool doesn't house the biologicals as well. Anyways, I'm not using them anyways, and I'm in coco, and the roots are healthy.

There was a time about a year and 1/2 back, when I was running an NFT system, same 6kw room, which I finally dropped because I couldn't get the water temps. Anyways, I had used the same system before, but 2kw, and did fine running botanicare's line, with hydrogaurd and everything was fine. Well, I move into this house and expand the system, and things went to shit. It was obviously root related, and hydrogaurd wasn't cutting it. So, I went the H2O2 route. Heavy H2O2 wasn't cutting it either. Finally, I picked up "rootshield" which is a commercial horticulture innoculant of Trichoderma Harzianum. After using this stuff my roots actualy started to come back to life.

Now, it turns out that "Rootshield" is actually IN Tarantula(or maybe Parahna, whichever is the Fungi). I've done some research on the subject, and basically the 3 fungi that have significant ebneficial properties are essentially just the endo and ecto Mychorrhiza and the Trichoderma Harzianum. Cutting Edge recently came out with their own, named "T-Harz" as well. Alot of the other ones in something like Piranha are really just useless fillers or even beneficials specific to other famalies, such as conifers.

Wow, that was off topic.

@ Black velvet - I'm not sure I should be amused or offended by that:smile: But I guess you never know. But yes, I def ph my rez when it needs it, which it doesn't often.

 

[MynameStitch]

Hey 20K how ya doing man
You got enough calicum in that system? What water are you using? Tap? RO?

Edit: I just read you did not use cal mag; well now is the time to do so! Your issue is simple calicum deficiency!

Also when you use COcO you wanna rinse it very well; even if the package says rinsed well.......

Get some calicum in them gals!

 

[scegy]

i usually have calcium related problems resembling in necrosis like yours, i'd agree with stitch on this one if it counts

intense light also helps to spread the necrosis, since the cells get unstable in the lack of Cal, the best Cal def. signs are those in the back of the necrosis, light green patches(chlorosis) in between the necrosis

mg and cal often rival eachother so, and excess of one could lead to lockout of the other + u've got burned tips which is related to ppm overdose as u know

 

[Guest]

JUst an fyi for you sick plant gurus....

Necrotic spots are not all made the same....

Calcium def can in fact cause them....

If you look at the third pic.....

the necrotic spots have a darker brown edge to them.....

this is a sure sign that its calcium......


one of the best pics Ive seen of a calcium def.....


Better than the ones in ole stitchers guide.....


lol.......

Here is a comment reguarding coco...... which tends to confirm calcium def....


"Coir does tend to hold calcium a little more than the other elements as well as releasing extra potassium."

20kw.... I was wondering....

do you have any leaves where the spots are just starting......

Im always curious once a good diagnosis is made to see how the def starts on a leaf......


tia.....

 

[sativalicious]

Thanks all, this is very informative.
Best lecture series ever!

So, to get a good diagnosis, it appears very productive to present the leaf... closeup like this. If I post a pic I will make sure and do it this way.

How does one get green veins like that? My center leaf vein is red, and the redness appears to slowly be receding away from my tip, and becoming green, as I have been coming off an alkaline condition. We all got issues, man... And I'm learning so much by reading excellent threads like this one.

I look forward to seeing the pic of the issue before they get as bad as necrosis. (as florigen2 mentioned)