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Tending Your Reservoir for a Full pH Swing and Cleaner Cannabis

hyposomniac

Active member
The pH charts posted by DC have been the scientific model for many years. Used throughout the Ag community and and the USDA.

This link might help.

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_053293.pdf

Thanks for the link, it's a nice chart and it references where it came from, and that manual may describe the process of determining their chart, which would be most interesting. I will look into it. It is also a soil chart..

Now I did not see a chart posted by DC, that you make reference too. I look forward to seeing that chart.

I want to make sure we're all looking at the same material.
 

Douglas.Curtis

Autistic Diplomat in Training
I actually haven't posted any charts yet, and don't even have any links to them for sharing. They're readily available online with a quick search <hydroponic pH chart>.


I don't trust any of them for pinpoint accuracy and treat them as a general guide. What's known is the 5.3-6.0 root-zone pH needs for cannabis. The charts make it easier to see what's general available and not at each range. :)
 
X

xavier7995

Good thread DC. I always enjoy your posts, you give the best description of what i consider good weed. I dont think my grows are there yet, but its nice to see something as an ideal target. Appreciate the tips on getting there.
 

Douglas.Curtis

Autistic Diplomat in Training
Thanks for stopping in, xavier7995. :) I'm glad you enjoy what I share and look forward to your progress. When you're exhaling massive flavor and aroma, it's difficult not to smile. lol

You'll get there. ;)
 

Dirt Bag

Member
Alright. I agree that companies want you to use as much of their products as possible. Even more. They'd like it if you just bought and dumped it down the drain in 55 gallon drums. I get that.
But there's also a sound, logical argument against the method you're describing.
There is no way to know how much of which nutrients have been used by the plants and therefore no way to add them back accordingly. Doing so arbitrarily will result in an imbalance.
This is the main reason we change the reservoir.
If you can logically explain how you're overcoming this dilemma, it would save countless growers an immeasurable amount of time and money. Me included. Not to mention the increase in hetb quality.
I'm not saying that the entire hydroponic community is right and you're wrong, I'm just suggesting that it's possible.
I do believe that we could possibly be using too much nutrients and am in the process of experimenting with lower levels. Our biggest problem with experimentation is the sheer cost as our reservoir is 100 gallons.
 

Douglas.Curtis

Autistic Diplomat in Training
You're using a massive amount more nutrients and water than you need. This is the difference between a properly balanced nutrient profile and one which is not.

To drastically over-simplify it:
When you're given a plate with steak, mashed potatoes, gravy and green beans, anything you don't need or won't eat is left over. Too much beans, and your plate comes back with beans left on it. Not enough of one or more items and though the plate is empty, you're still hungry.

When the mix is balanced and of the correct strength for the needs of the plant, there is no excess or deficiency. The plate comes back clean and the plant is full. While the exact balance varies depending on conditions and strains, a general base formula has been used successfully by growers for decades now. 122-99-171-68 N-P-K-Mg is what's been tossed around and it's what I've been using for 15+ years.

When this is used with a full pH swing in the root zone, allowing each element a period of full absorption, there is so little left over from errors it doesn't matter. When you add the balanced mix back to replace what the plants have used, it's all in balance. When you use a natural pH swing, without any manual pH adjustments, there is no build up of pH up/down elements from this source.

This is what cleaner cannabis is all about. This is the 20+ year old tech I'm working on teaching more folks about. This is what the common hydro community doesn't understand, and the ignorance the mfg's take advantage of. They sell a hell of a lot more nutes when folks dump their res every two weeks, that's for sure.

Do your own testing (I recommend a smaller personal grow, perhaps?) and reap the rewards for yourself.
tiphat.gif
 

Dirt Bag

Member
You're using a massive amount more nutrients and water than you need. This is the difference between a properly balanced nutrient profile and one which is not.

To drastically over-simplify it:
When you're given a plate with steak, mashed potatoes, gravy and green beans, anything you don't need or won't eat is left over. Too much beans, and your plate comes back with beans left on it. Not enough of one or more items and though the plate is empty, you're still hungry.

When the mix is balanced and of the correct strength for the needs of the plant, there is no excess or deficiency. The plate comes back clean and the plant is full. While the exact balance varies depending on conditions and strains, a general base formula has been used successfully by growers for decades now. 122-99-171-68 N-P-K-Mg is what's been tossed around and it's what I've been using for 15+ years.

When this is used with a full pH swing in the root zone, allowing each element a period of full absorption, there is so little left over from errors it doesn't matter. When you add the balanced mix back to replace what the plants have used, it's all in balance. When you use a natural pH swing, without any manual pH adjustments, there is no build up of pH up/down elements from this source.

This is what cleaner cannabis is all about. This is the 20+ year old tech I'm working on teaching more folks about. This is what the common hydro community doesn't understand, and the ignorance the mfg's take advantage of. They sell a hell of a lot more nutes when folks dump their res every two weeks, that's for sure.

Do your own testing (I recommend a smaller personal grow, perhaps?) and reap the rewards for yourself. View Image

And how do you obtain 122-99-171-68 N-P-K-Mg with GH Flora?
 

Hydro8

Member
There is no way to know how much of which nutrients have been used by the plants and therefore no way to add them back accordingly. Doing so arbitrarily will result in an imbalance.
This is the main reason we change the reservoir.

This is one of the big flaws of Douglas.Curtis PH swing "method". I suspect his plants are starving for certain nutrients so the swing the PH searching for them.

If this was a real scientific experiment Douglas.Curtis would be testing and replacing the depleted nutes in his old spend solutions. I highly doubt that he has this type of equipment or knowledge that extends to that level.

The reality is old nutrient solution, deprived plants and a big enough ego that anything one does is magical.
 

Bobby Boucher

Active member
I don't blame yall for being skeptical.

I've been peddlin pot since before I had hair on my nuts, and I feel very fortunate to have met and gotten to know the man who grew the best smoke that I've ever seen.

He grows using this same methodology, except instead of topping off with nutes, he does change out his nutrient solution every week. He also utilizes cane sugar or blackstrap with hygrozyme throughout flower.

I wouldn't be sitting here talkin smack if that smoke wasn't so so so so so so so so so much better than everything else I've ever seen. The only thing I have to contribute to this forum is a steadfast confirmation that when done right, this technique produces other-wordly buds that make the status-quo look like a bad joke.

Also.. there are a ton of people here who don't dump and grow dank. Which begs the question, how familiar are the naysayers here with the forum?
 

Hydro8

Member
Also.. there are a ton of people here who don't dump and grow dank. Which begs the question, how familiar are the naysayers here with the forum?

Cannabis is a weed, it will grow in almost anything. It is fine to not dump your tanks the plant will survive it is when you start claiming your "method" is the only true one for dank pot you invite people calling you out on it.

I've been peddlin pot since before I had hair on my nuts, and I feel very fortunate to have met and gotten to know the man who grew the best smoke that I've ever seen.

"peddlin pot" and having no hair on your nuts is not something that brings credibility to an adult discussion.
 
There's is a scientific study into this done by Bruce bugbee. It's worth a read. He has P no where near 99mg/L for tomatoes.

Here are his three recipes converted from mM/L to mg/L in the green columns. mg/L is ppm.

picture.php


Peace
BL
 

Bobby Boucher

Active member
I couldn't think of a humbler way of saying that I've been most everywhere and seen most everything. Most people never get the opportunity to travel as much as I have, or simply aren't as socially connected.

I've seen a lot of weed is the only point I'm trying to make here. If I hadn't, my 2 cents wouldn't be worth a shit. Everybody can think back to "that one shit" that blew everybody away, but not everybody gets to grow up down the block from the guy who grows it.

FWIW, I'm a pretty uninformed moron, in most every way conceivable, and I applaud you for pointing it out, but that doesn't take away from the fact that you could smell a gram of dudes pot from a mile away, and that he grew it using similar methodology.
 

Douglas.Curtis

Autistic Diplomat in Training
Thank you Absolom, very helpful links. :)

Dirt Bag, you can get rather close with a 1:2 ratio of GH Flora Micro:Bloom. It's become known as the Lucas Formula. The ideal is closer to 7.5ml Micro and 15ml Bloom, but the 1:2 ratio still works well.

"Personally," I believe the mix is a touch shy on calcium, which may account for many situations of easy root rot. I'm doing some experiments this winter to see the difference. Thanks Slownickle, I greatly appreciate what you've been attempting to educate us on. :)

BobbyBoucher, it's great to see we have the experience of sublime cannabis in common. :) Amazing how it's really more rare than people are generally aware, yeah? Thank you for speaking up, I greatly appreciate it.

Hi Douglas,
Not here to stir you up, but a couple things need addressing.

Re: these hydro charts,
I would very much like to see a definitive one, with scientific reference.
As far as I can tell, they are all derivative of one another with minor arbitrary changes and no reference to how it was decided.
Also many of them show brick walls at the absorption limits, vs a few that show a tapered line of lowered absorption.
If you're going to call these charts your facts, then we should have a proper reference chart.
I'd like to see an accurate chart as well. Perhaps one will appear in time.

The 'fact' I'm pointing out is there's a full healthy range of pH absorption, where each element has it's peaks and valleys. The scientific fact is more of each element can be absorbed properly when it's given the proper pH. This translates to being able to feed a lower amount of nutrients to reach a 'full' plant.

The charts are generalizations people have come up with. I have never posted any and do not refer to them other than as generalizations.

And sorry, but you can't decide that a public post is not for debate. If you make claims, some will challenge them; if your theories are sound, you can defend them.
I am here solely to make clarifications where it's possible for my knowledge and experience to do so. It is definitely not a debate.

Hydro8. The stronger the human psyche believes a lie, the stronger the emotional reaction is to the truth. In the end, we're all human and this is how it goes. We can see you're upset and I hope you work through it. You're the only one who can change this for you.


As for not dumping your reservoir until harvest, commercial hydro operations do not dump their reservoirs unless they have to. Could you imagine mixing a 2,000 gallon tank every 2 weeks? You could open a business selling depleted nutrient solution to small farmers. Sheesh.
Cornell University: A Recipe for Hydroponic Success (pdf)
UCSC: Water and Nutrient Re-use in Closed Hydroponics (pdf)


Robbie_Nood, I know nothing about tomatoes so I don't feel qualified to comment.
 

Dirt Bag

Member
... He grows using this same methodology, except instead of topping off with nutes, he does change out his nutrient solution every week...

So... not the same methodology at all.

Absolem, I understand ratios, however GH Flora is already mixed. To achieve specific ratios one would need separate nutrients. Unless those numbers DC posted just happen to be the sum of those parts combined which would be both/either complete coincidence or totally unnecessarily over complicated.

The theory that plants will absorb the exact amount of nutrients in the amounts replaced (dinner plate comparison) strays too far outside the realm of reason. One simply cannot know how much of which nutrients have been taken up by plants without scientific analysis, the form of which is almost certainly beyond the grasp of everyone but those fortunate enough to have access to a laboratory and the necessary equipment.
Since my mass spectrometer is still in the shop, I am going to stick to changing it out. I will however be using weaker nutes and seeing what happens.

Ahaha! By the time I typed this you responded. Lol! If its just lucas, then I'm game. It's what I started with in maxibloom. &#55357;&#56397;
 

Absolem

Active member
So... not the same methodology at all.

Absolem, I understand ratios, however GH Flora is already mixed. To achieve specific ratios one would need separate nutrients. Unless those numbers DC posted just happen to be the sum of those parts combined which would be both/either complete coincidence or totally unnecessarily over complicated.

I don't think you understand how ratios work or you would have never asked DC to come up with a formula for you. When I ran the GH flora series I was able to manipulate those three bottles into any nutrient formula I wished.

There is no way to know how much of which nutrients have been used by the plants and therefore no way to add them back accordingly. Doing so arbitrarily will result in an imbalance.
This is the main reason we change the reservoir.



NOT TRUE. As DC pointed out major hydroponic farms don't change their stock tanks weekly. They make and sell individual probes to measure each nutrient in the stock tanks so the nutrient solution never falls out of the desired NPK's. When the stock tank gets low it's filled up with fresh water then individual fertilizer injectors add the appropriate level of each nutrient to the stock tank until the probes tell them when they have reached targeted nutrient strength.

https://www.cleangrow.com/product/nutrient-analyzer/
 

Bobby Boucher

Active member
I've challenged Douglas on this before without getting a satisfactory explanation. I've always thought conserving nutes and water was for dirty hippies and commercial growers, and I still do to an extent, but I see a lot of dudes here growing hydro very successfully without dumping. Must not be too big a fuckin deal if they don't care to change their method.

FWIW, I can't get my ph to behave as predictably as doug's or my mentors, and i have a ph controller locked at 5.8 and don't really notice much of a difference. I don't really have a dog in the race. All I'm saying is that I've seen a ton of pot from all over the country and the best I've seen was grown using a "just add water" approach, swinging the ph from up from 5.6-6.3 if I am remembering correctly, and then bringing the ph back down with fresh nutes.

I'm no sock puppet either. Dougs a cool guy or whatever and contributes a lot here but i got better things to do than yank some fuckin strangers chain. It's not like he invented this method to begin with.
 

Earlmarne

Member
I run a ppk system. I go months without changing my res.
I input around 5.0 every few days. Brings me to 5.6 then swings to 6.1 or 2.
Seems to be working great.
My ec input is 1.4 that with dehumidifier draining into res keeps me at 1.0 to 1.2.
This is in my flower room. I keep ec higher in veg 1.4 1.6
 
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