Mid-Flower Defciency in Coco Top Feed?!

[Johny1212]

I am having issues at week 6 of flowering. This is Nirvana Black Jack in a top drip system with dyna-gro nutrients. I noticed brown tips about 6 days ago and I am also seeing these necrotic spots. I am thinking it is a calcium deficiency which is common in coco. I did a foliar feed on the big fans this morning with some GO CAMG+ to be safe. I am looking for opinions on what this is and if it will affect my yeild in the end and any possiblr solutions to keeping it at bay. This should finish in 3-4 weeks max. Here is my setup-

6x10 sealed room with CO2
2x 600W Agromax dual arc on nextgen digital ballasts..
Hoods are air cooled and draw from outside to outside. I control temp with the speed of the fan.
Running 1500 PPM CO2 on cheap controller
Temps around 85F
Humidity is at 45-50%
Nutrients are Dyna-Gro Grow, Bloom, Protektand Mag-Pro
I also use some H&G Roots Excelerator and Great White for healthy roots.
Medium is 50/50 coco/hydroton with 1 Tbsp Dolomite Lime per gallon of mediumfor calcium.
These are in 5 gal. grow bags and top fed to waste.
I keep PH at 5.8 and res temps around 66F.
Currently running 1.0 EC with RO Water-
4 ml bloom
1 ml grow
3 ml mag pro
2 ml protekt
2 ml floralicous plus
All are per gallon.
Any help would be greatly appreciated!

 

[darkhorse]

looks like calcium or magnesium def to me.
but your putting that in already?

 

[analogue]

calcium deficiency

 

[Johny1212]

Thanks guys. Should I hit em hard with cal mag? I don't want to make it worse. Do you think they are gonna suffer in yield?

 

[BlueJayWay]

I have the same on a couple plants, see my thread "mid-flower issues," after getting a dozen different responses i've determined the ones with the same "spots" is either magnesium def. or potassium def. I skimmed through some books and the signs are classic for either. I think also a lack of magnesium will prohibit the plant from uptaking potassium so there is a correlation between the two. Mine are further along and yellowing as well as the rust spots. I've fed with a 1-1-16 seaweed fert and some micronutes, if i notice a positive change i'll post up on it.

 

[BlueJayWay]

you can go as high as 15ml/gal for calmag+ @ your stage in flowering, it wouldn't hurt - since you're using RO.

 

[Stond_Face]

I run coco in drip and e&f.

I would take a plant and run some PH'ed water thru it and measure the EC of the run-off. If you see a much higher EC in the run-off, consider a flush.

It's usually a bigger problem for me in E&F than it is in drip, but, I get salt buildup in areas of the medium. This leads to leaf curl, burnt tips et.al... This is due to lock-outs because of excess fertilizer salts in the medium. ( Don't add more stuff to the rez to try to solve this)

Now, every 2 weeks or so, I'll chuck a Mag-Drive pump with 6 feet of hose in the rez. I fulsh the plants with rez water using the hose and run a few gallons thru each plant.. When I do this I see the rez raise a few points EC.

 

[Johny1212]

Thanks bluejay. Funny, I was looking at your post this morning and got pretty confused. I am going to up the cal mag to be safe. I like your thinking on the lack of mg preventing propper uptake of k

 

[Johny1212]

Thanks stond! I think I will do a flush then up the cal mag to 10 ml a gallon and see what she says.

 

[Stond_Face]

It looks like you are using high quality nutrients. Your nutes probably contain EVERYTHING the plant needs. Especially since your'e adding extra CalMag type stuff.

With that in mind, any problems you have are probably due to somthing like a lock-out or an environmental factor.

 

[darkhorse]

i got told to lower ppm a little when adding it.

 

[delta9nxs]

"Currently running 1.0 EC with RO Water-"

your dose is too low for a plant in flower with that type of lighting. try at least 750 ppm at the .5 conversion or ec 1.5= 1.8

 

[Johny1212]

Gotcha, I will just flush the shit out of them this afternoon and resume the same schedule tomorrow. It's late in the cycle so I guess success will be just keeping it at bay. If it progresses I may up calmag but not for a few days while the flush comes into play. Thanks for everyone's help!!! I will update with results.

 

[Johny1212]

"Currently running 1.0 EC with RO Water-"

your dose is too low for a plant in flower with that type of lighting. try at least 750 ppm at the .5 conversion or ec 1.5= 1.8

Yeah it's the lowest I've run but best results until this. I worry about upping because at this stage it is hard to tell signs of over fert. A friend runs .84 EC with the DG nutes and no deficiencies. I am torn on this one.

 

[SeaMaiden]

How long do you plan on running this girl? If it's going on 8 weeks, don't start pushing more feed now.

That's not a calcium deficiency, it's a problem with potassium and phosphorous. Reddened petioles indicate a problem with phosphorous uptake, the uneven mottling that occurs not on leaf margins, veins or interveinally is potassium. When the necrosis (brown spots) is even in pattern, occurs mid-plant or on the upper leaves, occurs on leaf margins, veins or interveins (between the leaf veins) then that is a calcium deficiency (or toxicity, many, if not most toxicities look just like deficiencies). Potassium and phosphorous need to be balanced in order to play well together.

So, whole plant pix will help better determine what's going on, along with those closeups you took. But right now my money's on an imbalance of K and P (easy to do consider coir's higher K content).

Also, because you're growing in coir, don't start flushing with Clearex or plain water until you're closer to pulling them. If you're going to flush, make it a very low EC flush, 1/3-1/4 nute strength is a good start for that. Otherwise you may cause more problems than you started with.

Let your pH range from 5.8-6.2 when growing in coco, that's important with ANY medium because nutrients are not all available at the same pH. That could be part of the problem. I would not continually use the Roots Excelurator, either. It's not only expensive, but unnecessary once the roots are well established, IMO. I am unfamiliar with the other products you're using, so can't speak to those.

 

[Johny1212]

Seamaiden. Thank you, this is very informative. So far I just flushed them with 1/4 strength nutrient solution and I am putting them back to my old schedule today. I have not been using roots excellerator for a few weeks. The great white is a myco product and I haven been using it since week 3 of 12/12. I think the plants are drinking enough that I am not getting any runoff in my afternoon feeding causing possible salt buildup. The PH thing makes alot of sense. I have been staying at 5.8 religiously so I will start to let it change around more when topping or refilling my res. She should have 3 weeks left so I am trying not to aggravate things Anyway, this is just excellent advice and very detailed. I really appreciate you taking the time to help me out. I will post an update this weekend when I can see if it is progressing.
Also- Does anyone have a way to figure out NPK ratios when mixing nutrients? I want to make sure my mix has a decent ratio but cannot find a way to calculate these.

 

[SeaMaiden]

While I haven't used GW specifically, if it's a live product, assuming you're not killing off the very microbes it's meant to inoculate the media with by using chemical salt-based fertilizers (again, I know nothing about Dyna-Gro, very, VERY rarely visit hydro shops or use them online), then you should not continually need to re-inoculate the media with the organisms. I hear great reviews, know more than a few people who like the results it gives them, but I personally am not so sure it needs to be added over and over again, because if it's a live microbe you *should* be able to keep it going (culture), kinda like a yogurt of a sourdough base.

I actually left a lot of detail out of my response, I have physical therapy today and don't have much time. I am not the person to ask about math problems, I just add the numbers, but I don't know if this is the correct method, and so actually prefer to go by what the plant is telling me is going on. And that's the thing that's great about growing in coir--things happen FAST. So that means that while it can go downhill in a hurry, you can correct the problem in a hurry.

I am also a DTW woman, the closest thing to a 'reservoir' I've ever done/used is pre-mix my (chem salt) ferts a few days in advance, keep 'em bubbling, in a 5gal bucket.

***Uh... how long did you say you're planning on letting them go, again? They look as though they could go 3-4 weeks or so to me. You could get yourself some SERIOUSLY fat buds off those ladies.

Oh! since I'm on my desktop, let me include a couple of attachments that I always find extremely helpful in making a (more accurate?) diagnosis of plant problems.

 

[Johny1212]

Thanks, you are just a wealth of information I have been looking at my NPK ratios and I think I am way off. I calculated my npk of the current mix at 1-6.14-2.85. Most people seem to like 1-3-2 from what I have seen. The mag-pro has a lot of p (2-15-4) so I think that is just throwing me off. I figured out a mix with npk 1-3-1.9 if I remove the mag pro. Then I could add general organics camg+ at 5 ml/gal which has 0 npk to make sure the have calmag available. I think that makes the most sense at this point. Overall they look fine but I want to get this straightened out and I can learn some things in the process. Let me know your thoughts on the npk ratios. Cheers!

 

[gonzo`]

How long do you plan on running this girl? If it's going on 8 weeks, don't start pushing more feed now.

That's not a calcium deficiency, it's a problem with potassium and phosphorous. Reddened petioles indicate a problem with phosphorous uptake, the uneven mottling that occurs not on leaf margins, veins or interveinally is potassium. When the necrosis (brown spots) is even in pattern, occurs mid-plant or on the upper leaves, occurs on leaf margins, veins or interveins (between the leaf veins) then that is a calcium deficiency (or toxicity, many, if not most toxicities look just like deficiencies). Potassium and phosphorous need to be balanced in order to play well together.

So, whole plant pix will help better determine what's going on, along with those closeups you took. But right now my money's on an imbalance of K and P (easy to do consider coir's higher K content).

Also, because you're growing in coir, don't start flushing with Clearex or plain water until you're closer to pulling them. If you're going to flush, make it a very low EC flush, 1/3-1/4 nute strength is a good start for that. Otherwise you may cause more problems than you started with.

Let your pH range from 5.8-6.2 when growing in coco, that's important with ANY medium because nutrients are not all available at the same pH. That could be part of the problem. I would not continually use the Roots Excelurator, either. It's not only expensive, but unnecessary once the roots are well established, IMO. I am unfamiliar with the other products you're using, so can't speak to those.

this is very sound advice... the other thing is that you're using very unbalanced amounts of nutrients aren't you? i'm in coco with ro water and i'm just using canna coco A+B and I'm not adding CalMag... I think everything you're adding is causing an imbalance... Your base nutes should be making up the majority of that 1.0 EC.. You should check just to be sure.

 

[Johny1212]

Thanks gonzo! What are your thoughts on my last post about my npk?