Crop Steering in coco. How to determine optimal EC?

[cannalyst]

The conductivity measurement isn't very useful beyond verification of a known solution.

In order to deliver precision nutrient you'd need to calculate for the elemental requirement of the plant and dose accordingly.

Nutrient lines abstract away this knowledge for profit and have everyone blindly dosing their crops to mixed effect.

 

[Ca++]

Dosing individual elements is awkward, even if you can measure what's been taken.
If we had the perfect feed to start with, the speed the plant takes each element, isn't equal. The K might be taken in hours, and putting it back at the rate it was vanishing, would be toxic. We see N studies of 160ppm in dwc, but that solution might last a week, with a top up solution being used, that doesn't have everything in it. If we keep N constant, it's more like 30ppm needed.

Now as we look at our commercial feeds, we should be able to see that one suited for 6 fertigations per day, may not be so suited for a DWC meant to run a few days. Some feeds will talk of using less EC with higher frequency fertigation. It's hard to be more specific with their formulations, as all our plants differ somewhat in their daily needs.

It's not all doom & gloom though. We have people here, doing well, with tanks set for long term us. There is an idea that the feed is either in the tank, or in the plant, it can't escape. So all you really need do is top up. Which they do with the same feed. It works. Though in fact, the top up feed should actually be a bit more specific. If we could formulate that. It has a name, but it's not engaging my brain right now

 

[LostTribe]

Jacks 321 full strength. Make sure you get 15% runoff every watering. Nothing more nothing less. You arent going to re invent the wheel. And LED sucks in my very honest opinion due to lack of heat for your root zone and your leaf zone FYI. No point in LED as this fad came around for the cost saving of running these lights. Well they dont take into account you will have to run heating directly into the garden to compensate which defeats the purpose and nullifies any cost savings whatsoever.

 

[LostTribe]

yeild of green plant matter is not the goal. Fat trichome heads is the goal. HID reigns king.

 

[Ca++]

If you are going to practice crop steering with a couple of drybacks late stretch, then an organic soil grower need not worry, but a more hydro like (available food in water) might mean a lower ec for those times. To combat the expected rise.

This is all in flux really, but hard dry backs in veg likely trigger a veg response, that involves growing a bigger root system to assist if it happens again. Growing a bigger root system is nice, though you might not want to spend time doing so.
Later in bloom, we pretty much can't grow a new root. Not watering, will be more like a trigger to stop getting bigger, and hurry up.
Reports are still coming in, but there is a strong lean towards losses when people try and steer with dry-backs during bloom. They are a vegetative trigger. To be used when vegetative root growth is wanted.

Next year, I might be eating my words. This is where we are today though. Withholding during bloom, is just looking a bit crazy, as we work faster and faster plants. The long flowering guys might tease out more roots though, if for some reason they didn't have a good veg period.

 

[XYZVector]

So the EC they are giving isn't the inflow EC it is the Pore EC of the media. This is not the same as the EC of the nutrient solution your feeding the plants. Pore EC consists of the temperature of the media, it's water volume content, the dielectric constant of the media, and the inflow EC of the nutrient solution. In order to properly crop steer you need a special media sensor. These sensors cost 300 bucks and the aquisition system is about $500-$2000. Then you need a system that can take the data and generate the correct fertigation cycles based off the data the media sensor(s) collect. You can approximate it but unless you know the PoreEC of the media it is hard to get right without burning your plants with salts. I built and programmed my own crop steering system, and there are sources of media sensors that are 10x cheaper than the ones they are selling. However you have to know how to program, and talk to these sensors.

 

[RuBp]

Everyone gets stuck on crazy high EC as the only way , when its not the only way to accomplish the same goal, and probably not the best option in coco at least. You control the environment, you control the amount and type of growth. I got a feeling a fertilzer maker/seller brought crop steering to the weed world, its normally just called hardened off growth or rank growth in the nursery/greenhouse industry.

 

[LJ farming]

Jacks 321 full strength. Make sure you get 15% runoff every watering. Nothing more nothing less. You arent going to re invent the wheel. And LED sucks in my very honest opinion due to lack of heat for your root zone and your leaf zone FYI. No point in LED as this fad came around for the cost saving of running these lights. Well they dont take into account you will have to run heating directly into the garden to compensate which defeats the purpose and nullifies any cost savings whatsoever.

Damn Right Lost Tribe! You helped me understand this a lot better a few years ago!

The plant will not take .1 EC more than it requires so everything else goes down the drain!

 

[LJ farming]

If you are going to practice crop steering with a couple of drybacks late stretch, then an organic soil grower need not worry, but a more hydro like (available food in water) might mean a lower ec for those times. To combat the expected rise.

This is all in flux really, but hard dry backs in veg likely trigger a veg response, that involves growing a bigger root system to assist if it happens again. Growing a bigger root system is nice, though you might not want to spend time doing so.
Later in bloom, we pretty much can't grow a new root. Not watering, will be more like a trigger to stop getting bigger, and hurry up.
Reports are still coming in, but there is a strong lean towards losses when people try and steer with dry-backs during bloom. They are a vegetative trigger. To be used when vegetative root growth is wanted.

Next year, I might be eating my words. This is where we are today though. Withholding during bloom, is just looking a bit crazy, as we work faster and faster plants. The long flowering guys might tease out more roots though, if for some reason they didn't have a good veg period.

IMO not one root is grown after Stretch! So veg is 100% over after transition and feed the flowers! N gets reduced the final 5-6 weeks as well!

 

[LJ farming]

Everyone gets stuck on crazy high EC as the only way , when its not the only way to accomplish the same goal, and probably not the best option in coco at least. You control the environment, you control the amount and type of growth. I got a feeling a fertilzer maker/seller brought crop steering to the weed world, its normally just called hardened off growth or rank growth in the nursery/greenhouse industry.

Absolutely bud!

IMO nutrients are the least important part! NPK and CalMag are baby shit easy!

Dial in Environment 1st, then light intensity, then environment again, maybe think about CO2 then perhaps you might need more than 1.5-2 EC! I seriously doubt it! Nutrients are the easiest and cheapest thing to manipulate and most get hung up on them.

The plant will only uptake a certain amount of nutrients!

Worry about EVERYTHING ELSE first then maybe mess with nutrients!

1.5-2EC is ample in my experience! Closer to 1.5

 

[LJ farming]

Absolutely bud!

IMO nutrients are the least important part! NPK and CalMag are baby shit easy!

Dial in Environment 1st, then light intensity, then environment again, maybe think about CO2 then perhaps you might need more than 1.5-2 EC! I seriously doubt it! Nutrients are the easiest and cheapest thing to manipulate and most get hung up on them.

The plant will only uptake a certain amount of nutrients!

Worry about EVERYTHING ELSE first then maybe mess with nutrients!

1.5-2EC is ample in my experience! Closer to 1.5

If your light intensity is less than 40-50 watts per sqft More/different/better nutrients will never do anything besides take money outta your wallet!

 

[Ca++]

~day 18, it's likely the runoff EC will jump. Some watch for the pH drop that comes hand in hand. This is a good indicator you need to switch to bloom foods, and so is the cornerstone of a steering event. Switching feed earlier might lead to weaker plants, and any later to a weaker bud response.

Looking at the plants, this is the transition from stretch to bud. At this time, water use increases. Buds and there hairs that want keeping moist, don't have the stomatal regulation of leaves. Instead, they loose a lot of moisture, that didn't actually need to bring so much feed with it. The root system becomes worse at the passive intake of calcium now. All leading to higher water use, so we see the feed left in the pots increase.

Some will increase runoff to control this EC increase. Others will reduce EC to try and maintain the rootzone EC in range.

It is something to watch for, and respond to. It is the crop steering us, it would seem. The recirc guys would be changing their tank perhaps. Which might of jumped over 25%.

We are still some way off knowing enough about what's really happening, so just take this post as ideas, and possible explanations.

 

[LJ farming]

Decrease your ec into 2.0 in the early flower, and 1.5 in the final weeks. I run 1.6 all the round and works great for me. Sometimes I run 2.0-1.8 in early mid flower. But in week 5 onward I have to drop to 1.5-1.6
Target your ph accordingly to your runoff. If it tend to up go with 5.8, if it tend to down run 6.3.
And if you want to be safe, do a little flush per week with your solution in half charge.

No worries to little burnig tips.

When I'm running Lucas Formula (GH) i dont use calmag. I think floranova dont need it needer. Calmag is just Calcium Nitrate and MG Nitrate in most times, and you have 4%Ca and 2%MG in Floranova its enouth. I run with leds and never had a defiency without Calmag runing GH basic nutes.

You are definitely on the right track! I never run over 1.5-1.8 EC

 

[PlastikeRubba]

Those suggested EC figures can't be accurate because every strain is different, my Ghost Train Haze grow in coco for instance burns the tips at EC 1.5 so you need to up the EC gradually to find the optimum in my opinion unless crop steering is different than normal growing?

Which nutrient burnt your tips?

Pectate? Hordein? Glucose?

Oh it was EC? Some made up arbitrary value attacked your plants?

EC isn't a thing. If a mineral did something other than make plant food, tell us what it did.

Does this happen to humans also? Too many nutrients cause spontaneous combustion of your finger tips?

No. It makes people fat. And since cannabinoids and weed flavors are made from fats I fail to see how obese Cannabis is a problem.


EC BURN IS A MYTH. Overfeeding is a myth. Toxicity levels are determined by ratios of the chemicals participating in the chemical reactions, not "EC".

You couldn't get a job in a body shop mixing up bondo if you can't grasp that. The total volume of the mixture doesn't matter the ratios are what matter.

IMO nutrients are the least important part! NPK and CalMag are baby shit easy!

Bait thread. Troll post. Mids grower.

Not being sarcastic.

I used to think you people were a bunch of retarded sheep.

I've been watching armchair internet growers blame the environment for their boof since day one and just now realized it's a troll. I guess I'm the retard after all.

 

[Ca++]

Perhaps you are. Every serious grower knows that EC exists, and how to use it. If you can't grasp that, then all them other words are probably lost upon you.

 

[LJ farming]

Everyone gets stuck on crazy high EC as the only way , when its not the only way to accomplish the same goal, and probably not the best option in coco at least. You control the environment, you control the amount and type of growth. I got a feeling a fertilzer maker/seller brought crop steering to the weed world, its normally just called hardened off growth or rank growth in the nursery/greenhouse industry.

YUP

 

[LJ farming]

You are definitely on the right track! I never run over 1.5-1.8 EC

However have you ever looked at no N flowering CalMag? It dumps the pH because it’s Calcium citrate. However I can correct the pH and there is no N! Most say it’s wrong but I replace CalNit 20% per week with this! Calcium is the MOTOR for building solid fat Donkeys after stretch is over. N becomes Less important by the day after stretch.

in the US Growmore is what I use! Not sure about global suppliers.

If ya know ya know! Otherwise ya don’t!

Peace,

Bro Science GODFATHER

 

[RuBp]

LJ you need to decide if the roots stop growing at stretch or if Ca is the motor for building fat donkeys. Without new new root growth you aint getting any Ca uptake.

 

[LJ farming]

This is new to me bud! As far as I’m concerned after stretch the roots are the plumbing for nutrient uptake and the more roots the more fruits. New roots do not grow any longer you got whatever you got to produce the best flowers possible.

The plant needs a lot of Ca to grow correctly in Coco as well as possibly other grow media. This is why lots of growers use CalMag as a crutch to solve every issue they perceive! It works until it doesn’t. Then only runs under your belt will teach you how to adapt or you can stay the same and never improve!

I start lowering N weeks 4-9. I use a little More Ca and N during veg and during stretch. After stretch it needs less N but still needs Ca to perform! It also needs supplemental Sulfur to create the best terps when running salts in coco. So weeks 7-9 MagSul gets replaced by Potassium Sulfate slowly but surely!

Fulvic acid is one of the magic inputs in my opinion but what do I know.

 

[RuBp]

The only part of a root that can uptake Ca is newly formed growing points. If your roots are stopping growing you cant uptake Ca. Its because of the large size of Ca. You should look into how its translocated in the plant also, you will reconsider trying to slow transpiration. If you really want to learn get plant nutrition, physiology, etc books, the peckerheads on snappergram and instarchat dont know their ass from their elbow.