This is a P deficiency, right? If so, what now?

[clowntown]

 

[Guest]

whats up clowntown...i will tell you miss mud(im stoned mud doesent have the problem) is a pig she likes to eat...and it looks like you have had some ph fluctuations

 

[clowntown]

Hmm interesting about the pH... you could be right about that actually. When I mixed my 50L rez, I had set the pH to around 5.8... the next day it was around 5.8... then a few days ago, by the time I was almost out, I checked it again (after about a week after mixing) and it read like 6.1 - 6.2. Not sure what happened, had the lid on the Rubbermaid; does CannaZym cause that? Anyways two days ago when I raised the amount of A+B to 3.5mL/ea/L, I did check (when I noticed 6.1-6.2) and readjust to around 5.7 - 5.8 but that didn't seem to solve the problem... yet.

Anyways I took a closer look at the Mud's and they are starting to show the problem, just not as much. In the mean time I've upped my nute mix to 3.5mL/L for the time being for a 60L mix.

Also brainthor, take a look at the "Edit:"s at the bottom of the previous post... I think I may have edited it in while you were posting. And thanks for the response, you're most likely right about the pH.

I'm kinda regretting adding the PK13/14 now, even at 0.25mL/L, but hopefully that was a small enough dose that it won't matter... (Don't want to throw out a 60L mix of expensive nutes.)

Edit: Just checked my pH pen and it was off by .2. Read my new mix (before pH down) at 6.25; calibrated @ 7.01, and now reads 6.05.

 

[Blackvelvet]

The medium / nutes is Canna Coco medium, Coco A+B (3mL/L), Rhizotonic (0.5mL/L), CannaZym (2.5mL/L), CalMag+ (1mL/L), Silica Blast (1mL/L) and Liquid Karma (3mL/L).

Edit: I just added 0.25mL/L of PK13/14. The bottle-recommended usage is 1.5mL/L one-time for a week 3 weeks prior to harvest, so I hope this is small enough of a dose.

Here are some numbers for reference. This is in the hydro sticky "calculating nutrient profiles" by lucas. These are ml per gallon (3.8L)

canna coco 5.7a plus 5.7b (this is their baseline 3ml per liter formula), the highest dosage they recommend is 14ml/gal of canna coco A plus 14 of B). This mix (5.7ml/gal) is less than 1/3 strength of GH Flora Nova Bloom @8ml per gallon on the P, K and Mg..
N 87
P 30
K 43
Mg 17

canna coco 8/a and 8/b
121
42
60
24

Here is canna coco's strongest bloom mix, before the pk14 boost. it resembles the GH FloraNovaGrow recipe in its Nitrogen level
canna coco 14/a and 14/b
212
74
106
42

At 3 ml per liter, your using 11.4 ml per gallon. This gives you:
n 172
p 60
k 86
mg 34

You added about 1ml per gallon pk 13/14 which gives you:
p 17
k 35

cal mag plus 1ml per liter:
n 20
mg 12
ca 33


Comments: About the only observation I can tell you right now is 60 p is quite a bit. Your not seeing phosphorus deficiency. I think i would stop using cal mag plus and add epsom salts at 1/8 teaspoon per 3.8 liters. There are micronutrients in cal mag plus and more calcium that you may not need. The hydro sticky says canna coco nutes need epsom salts at 1/4 teaspoon per 3.8 liters. K at 86 is low for soil and hydro. I guess there is potassium naturaly in the coco? 172 n is strong. Then you added 20 more with the cal mag plus. Hydro and soil growers use about 100 ppm n for flower.

Sorry I can't help you more at the moment. Maybe you should post your problem in the new coco forum.

 

[Verite]

Is it just exclusive to the lower leaves that are 'touching' stuff? Or have any of the middle fans started showing signs?

 

[clowntown]

It appears to be exclusive to the bottom two pairs of nodes only, but I'm not so sure that all of them were affected by having the leaves touch / soak the solution. Then again, it could easily have as I've been hand-watering with a 1L measuring cup, squeezing that cup in there and splashing drops everywhere on a daily basis lately. Hmm...

 

[clowntown]

Just in case those were nute burns from accidental foliar feeding, and also to help me water with much more ease, I got this watering wand with an on/off lever. It extends to something like 6 feet long! I have fittings to hook it up to my 396gph submersible pump via 1/2". We'll see if this helps.

Thanks everyone for the help so far.

 

[Grat3fulh3ad]

Comments: About the only observation I can tell you right now is 60 p is quite a bit. Your not seeing phosphorus deficiency. I think i would stop using cal mag plus and add epsom salts at 1/8 teaspoon per 3.8 liters. There are micronutrients in cal mag plus and more calcium that you may not need. The hydro sticky says canna coco nutes need epsom salts at 1/4 teaspoon per 3.8 liters. K at 86 is low for soil and hydro. I guess there is potassium naturaly in the coco? 172 n is strong. Then you added 20 more with the cal mag plus. Hydro and soil growers use about 100 ppm n for flower.

Sorry I can't help you more at the moment. Maybe you should post your problem in the new coco forum.

Your post are looking better to me, maybe you're begining to understand application as well as theory. This is one of the few times I've seen you take medium into account. Yes coco has K naturally, and a high cation exchange rate so It robs Ca- and Mg- from the solution as well.

looks like pH fluctuation to me, though... Are you sure it stayed between 5.8 and 6.2? Also lack of disolved oxygen comes to mind as a possibility?

 

[clowntown]

Lack of dissolved oxygen could definitely be the case, as it was a pre-mixed solution that had been sitting in a Rubbermaid container for a week. Would it affect only the bottom leaves as it did? pH fluctuation is also quite possible, and I recall now that when I checked the rez a week or so after mixing it had been 6.2 only after I added the extra 0.5mL/L of the A+B... so it was likely higher than 6.2 at one point.

For the time being I've clipped off the affected leaves to form a baseline, and see if the problem continues with reduced splashing on the leaves and pH checked more regularly. I'll also be watering with a sprinkler wand, so it will hopefully increase dissolved oxygen in the solution.

 

[Grat3fulh3ad]

If there is a pretty good chanch that the pH was higher than 6.2 and there was little disolved oxygen as well, then I think I'd bet on the mystery being solved.

 

[Blackvelvet]

Sorry I was really tired earlier.

Well its not magnesium deficiency. Your k to mg ratio is 2:1. Other types of growing have this 4:1 with alot more potassium. Unless your coco is giving you a big blast of k naturally , your going to see potassium problems with only 86 k from the ferts. If the situation does not improve with the disolved oxygen theory or whatever, I would drop the cal mag plus to reduce magnesium, use 3ml a and b per liter, and continue to add the pk 13/14 at .25 ml per liter. k to mg would be about 4:1 (121:34) That's great your getting alot of runoff with each watering.


.

 

[clowntown]

Not sure what's best for the dissolved oxygen... mix a new batch of nutes with new, aerated water from the faucet each watering (annoying), or air pump (afraid of evaporating P, and raising pH and having to add more pH down).

At first I wasn't even going to use any CalMag+ at all; but as early as seedlings they appeared to have calcium deficiencies. I added a little bit of CalMag+ and that went away, so I left the CalMag+ in. My tap water comes out at around 30-35ppm (@ .5), so there can't be much calcium in there. Folks say you should use some CalMag+ with RO water in coco, so I may fall under that category. What do you think?

 

[Blackvelvet]

That's why I figured the ppms for everything earlier today so you know exactly what the plants are receiving. The more I look at the pictures the more I lean toward potassium deficiency. Try the disolved oxygen theory and see what happens. I know you coco nuts water alot against my endorsement. Are you letting them get somewhat dry at least?

 

[Grat3fulh3ad]

Sorry I was really tired earlier.

Well its not magnesium deficiency. Your k to mg ratio is 2:1. Other types of growing have this 4:1 with alot more potassium. Unless your coco is giving you a big blast of k naturally , your going to see potassium problems with only 86 k from the ferts. If the situation does not improve with the disolved oxygen theory or whatever, I would drop the cal mag plus to reduce magnesium, use 3ml a and b per liter, and continue to add the pk 13/14 at .25 ml per liter. k to mg would be about 4:1 (121:34) That's great your getting alot of runoff with each watering.


.

Yup, back to normal now... diagnosing what you think is going to be a problem, instead of helping with issues at hand. Read up on coco and K.

dropping the cal-mag some is good advice, but to reduce N not Mg which coco can rob. Read up on coco and cation exchange.

watering to runoff in the coco should keep enough O2 in the root zone... they're not sitting in a tray which holds the runoff or anything? If not then the issue is gonna be more the pH thing, imho.

Who said sleep deprivation is a bad thing:wink:?

 

[clowntown]

They are sitting on top of a Botanicare ebb & flow tray, which has channels to ensure that there is no standing water. So with that, then I shouldn't have to worry about pre-dissolving oxygen into the rez prior to watering?

I'm watering them once a day now, at approximately lights-on. They feel a little bit lighter when I water, but I wouldn't call it anywhere near "dry".

I will keep a very close eye on pH. Right now it's at 5.8 - 5.85.

On the next mix, I will drop the CalMag+ down to 0.25mL/L and see if any calcium deficiencies come up again. Or should I do it now (is CM+ possibly the big culprit)?

 

[Blackvelvet]

Potassium would be held by the coco just like magnesium.

What CEC actually measures is the soil's ability to hold cations by electrical attraction. Cations are positively charged elements, the positive charge indicated by a + sign after the element symbol. The number of + signs indicates the amount of charge the element possesses.

The five most abundant exchangeable cations in the soil are calcium (Ca++ ), magnesium (Mg++), potassium (K+), sodium (Na+) and aluminium (Al+++).

http://www.ricecrc.org/reader/soil-types-structure/ss393-cation-exchange.htm

The ferts are 2:1 potassium to magnesium. I am pretty sure you should see potassium deficiency.

Then you go to the pictures and wow...burned margins on the bottom leaves.

Stoned again.

 

[clowntown]

So... recommended action?

 

[Grat3fulh3ad]

yeah... drop it now...


Close BV... more research will reveal that coco releases K constantly as it breaks down....

The deficiencies you see are more due to pH, than the ratio...

 

[Blackvelvet]

So... recommended action?

For 60 liters:

30 ml pk 13/14
120 ml a and b coco nutes
1 1/8 teaspoon epsom salts

n 113
p 74
k 127
mg 32

 

[Grat3fulh3ad]

If you look at a pH chart... as pH increases from 6.0 to 6.5 the available Mg and Ca increase rapidly, while the availablity of K remains fairly consistant... this is what was causing the cation competition...

Your diagnoses not far off, BV... but your reasons and solutions are more drastic than necessary...

Proper pH is more important than specific ratio.