calcium : magnesium ratio?

It's really all depends, how long has she been flowering, what have you fed her previously, and how many times?

Sometimes over feeding at a high EC can give you great results for a while but then the coco holds onto a few of the elements a little better than others (calcium and potassium). And because of a high EC fed over and over again over time might cause an excess of unknown ratio of nutes that could be causing a lockout. I think giving more calcium/mg might only worsen your problem.

What PH/EC/ NPK ratio are you feeding with?

 

If you're using soft water nutes and feeding properly it's very unlikely you'll encounter a calcium deficiency. Have you got pictures?

 

Calcium Nitrate is about 24.5% Calcium.
Magnesium Sulfate is about 9.8% Magnesium.

A 5:1 solution with water gives about 4.9% Calcium and 2% Magnesium (mixed separately).

Of this 5:1 solution you could use:
5ml/gallon of the Cal-Nitrate Solution for about 65ppm of Calcium
7.5ml/gallon of the Mag-Sulfate Solution for about 40ppm of Magnesium

Or you could run it at twice those levels... Really, how much of each to add depends quite a bit on your macro nutrient profile, the maturity of the media, and the nutritional requirements of the phenotype. There is no one set ratio of Calcium to Magnesium for all plants through all stages of life. The ratios are variable and due to slide around as the grow progresses.

Around the 15th to 30th days of Flowering many coco growers experience a Magnesium deficiency. What I like to do is begin flowering with a 3/2 ratio of calculated Calcium to Magnesium (about 90ppm Ca and 60ppm Mg) and I gradually increase the Magnesium (about in line with Phosphorus) while decreasing the Calcium to a point (about in line with Nitrogen). By the 45th day of the grow I may be running as much, or more, Magnesium as Calcium for some of my plants (in hydroponics, organics is different).

A quick remedy for early Magnesium deficiency, determined by the interveinal chlorisis prior to leaf necrosis, is to prepare a Magnesium centric foliar feed. I use 1/4 of a teaspoon in 1L of water with a drop of biodegradable dish soap (Ivory), sometimes with a few drops of Liquid Karma or Fulvic Acid. Direct the applied the foliar spray to the bottom of the affected leafs every morning for 3 days just as the lights come on, following up on the fourth day with a clean water foliar spray (to remove any salty buildup which could block stomata). An effective foliar program, with a redesigned nutrient profile to accommodate the need for more Magnesium, will quickly remedy a Magnesium deficiency and set the plant back on a healthy path.

I think that if you shared more information, regarding your nutrient system and the volume of each supplement used, you would get a better response. Posting a picture or three will help the community determine what the issue is while reassuring that you are applying the proper solution to the problem.

I wish you luck.

 

967, got some pics? and more details....
My advice is to be sure that you actually have a cal/mag problem before treating the plants. So many deficiencies have the same symptoms that can fool the eye...
I think a foliar feed as SCMC says would be the fastest and safest way to start before adding to the medium....To much cal etc can cause other problems like iron and zink uptake.

 

Mate, you definitely need to put pictures up. Don't go changing your nutes and making up home brews of cal mag before you do that.

 

What's the temp and humidity?...How close is the light to the plants and what size light?...What is the ph?

I see signs that look like mag deficiency(especially the flowering plants) but, could be due to the above. The yellowing is sometimes normal in late flowering.
If the above grow conditions is in check I would do a flush and start feeding a mild nute solution and see if theirs any improvement over the next week or so.
If you have canna nutes I would go that route because they are coco specific...

 

if your wanting to switch up nutrients for flower, i would suggest maxibloom

its a great one part nutrient. its what i use for all my flowering plants

alot of amazing growers i know on another forums really rock the shit w/ maxibloom

pm me if you want some links to some good threads with alot of info

 

I'd put good money on that being your problem right there mate.

I don't know if you've read any of my basic guide on the first page, but I make a point of highlighting it. If you read the first few posts, then read this thread back, I think the light will come on. Nutrients are useless if your roots are cold, it's that simple.

So many people diagnose deficiency of one element or another when the problem is almost always environmental. It's why I made a point of highlighting it. Too many people just don't understand the impact it can and will have if your roots get cold.

What you've got to realise is that most nutes on the market can be used to grow a plant to perfect health, even if some of them need a slight supplement -and I mean slight, and we're talking minor tweaks. If it's ever a nutritional problem then it's almost always down to the grower under or over using them. I've tried Ionic, Hesi, Biobizz, GH, and others, and the differences are minimal and hardly anything to do with the actual results they achieve and More to do with concentrations and additives which you either do or don't want in your bottle, such as artificial colours etc.

The only problem with the relation between cannabis and it's nutrients is the fact that most stand alone feeds contain slightly too much nitrogen for a flowering plant. Some varieties suck it up and some spit it out. If that ever happens you need to take a bit of the base feed out and put some pk in. Weeds are very easy things to feed and keep happy.

Keep the roots warm and the feeds simple my man and honestly you can hardly go wrong.

If you want simplicity and results, there's probably no better nute on the market than Hesi. Apparently maxibloom is the same - a pne parter which gets good results. Pick one for simplicity.

Just don't be under the impression that your nutrients are the cause of the problems, because the fact is, you're growing the same plant that everyone else round the world is, using the same nutes they do to get great results. That shows that the nutes themselves work and that the problem is something else.


GET

SOME

PICTURES

UP!!

 

The first two pictures show evidence of epinasty, Phosphorus, and Potassium deficiency.
It is likely that you have been overwatering (too frequently) since transplanting this plant. The root system has actually decayed as a result of insufficient dissolved oxygen levels in the media. There are many causes for this and even coco can be overwatered when the root system isn't mature enough to handle the constant level of saturation it will be able to when fully grown.

I recommend backing off on the frequency of the waterings, encouraging a better wet/dry cycle similar to soil, while increasing the amount of PK they have access to. If your vegetative nutrient system has the right ratio then I think simply a higher EC will benefit the plant when it is recovered. A kelp extract supplement, or maybe some superthrive, would help to speed the process of returning this plant to a healthy vegetative pace.

The third photo shows evidence of severe heat and/or severe Potassium deficiency. The reason the leaves curl up like that is to assist in evaporation and respiration and this is typically found in growing environments that are too warm. Potassium is an important element as well in the transpiration process and a deficiency of this element forces the plant into this position to maximize what little it can "sweat" to cool down.

In this plant I think cooler temperatures and an increase of Potassium (by as much as 25% the current level) will benefit it. Simply getting more Potassium to it will help the situation but I strongly recommend dropping the temperature and the humidity as well if you can manage it (an air conditioner would be fantastic if you have one to turn on). Otherwise just do what you can to keep your temps reasonable and stable and with the increase Potassium level this plant should continue rocking and rolling after a quick recovery stage.

There is a possibility that you have an excess of Calcium, Magnesium, and maybe Sodium which are impeding the uptake of what is actually a very proper level of Potassium already in your feeding solution. My process for helping to determine if it is build up that is the problem is to collect a decent amount of runoff, like 30%, and to test that with your EC meter. If your runoff is quite a bit stronger than the solution you are running then this may indicate a problem with build up in the media. The excess salinity can result in precipitation of elements as salts even in solution and that can cause the lockout you're seeing.

So, before really messing with the temperature or adding more Potassium to your solution first you should verify that the media is not retaining an excess amount of elements. Then apply the solutions I suggest and watch for improvement.

The last photo looks like a possible mild Nitrogen and/or mild Phosphorus deficiency. Given the stage of life, and the spread of the deficiency, this could be natural for this plant to consume some leaves in the last 15 to 20 days of life. I see some fox tailing so you are definitely about to build some serious buds here.

My thought is that some strains do eat a good amount of Nitrogen and Phosphorus (100ppm calculated of each, or more) well into the 6th week of flowering. This strain might be sitting pretty close to dialed, just a little more N and P, or maybe at this point just a little more P is probably better, and I don't think she'll look unhealthy or slow bud growth in any fashion. Sulfur is a possible culprit as many people don't realize that in the later parts of flowering Sulfate is present (mostly oxygen really, but still) in excess of 100ppm. There is nothing here to say that it is more likely to be any one, or a combination, of these element deficiencies. The fortunate thing is that whatever it is, it is not severe enough to warrant a severe reaction. A little more bloom nutrient should contain everything this plant needs, including the sulfur. Although, you must consider letting the plant run a natural progression of consuming the larger fan leaves as flowering concludes.

Feel free to check my diagnosis against the common descriptions for these deficiencies and issues with the root system and see for yourself if they match up. I usually suggest a "less is more" approach but in your particular case it seems like all your plants could benefit from a touch more of the elements only you can provide. Baby steps, not knee-jerks.

 

That vegging plant is showing typical signs of cold root syndrome and the only way to know whether that's your issue is to get a thermometer in and tell us the lowest point the temps are getting too. Anything below 18 and you've got your answer.

Never ever underestimate temps man. Without knowing whether it's cold in your room, the best growers in the world can't help you my friend. Get a cheap digital thermo and hook it up. Then get straight back.