bobblehead's organic bedroom of high brix gardening

[bobblehead]

I'll say that looks a whole lot better than previous runs, but it an't dialed bro. I see evidence of imbalances during your flush. When everything is dialed you come out with fall colors at the end (purple, pink, red, etc). Should be none of the typical signs of deficiency. Not the best example, but it will give you an idea of what I mean.

View Image

Notice how the green just fades into purple? Almost no yellow or rust coloration, because she has just enough what she needed to finish. The burnt leaf in the background is from getting too close the bulb.

Oh so like this DGSC#3 before I ditched coco 100% and switched to peat.

 

[megayields]

Oh so like this DGSC#3 before I ditched coco 100% and switched to peat.
View Image
View Image

Those buds look too crystally and full ..they need a good smashing....you need to sit on your bag to make them "look" right....you know to look like Cali buds all smashed and compacted! ;-)


lol amazing bro...just amazing and now I have to decide for next year (sigh)...peat or coco?

 

[bobblehead]

Very good info sir. Makes a lot of sense.

Unfortunately we have stripped off so much Sphagnum that it is running out. And it does not regenerate itself - so the Midwest will soon be in a pickle. Probably within the decade. Depends on multiple factors timing wise - but the price will probably increase over time.

Very well said Bobble - may I inquire on your opinion regarding Using Beneficial Microbes like say Great White Innoculent - with Synthetic nutes in Coco? Not sure if its needed - necessary - will make things better - or just over kill... Zero root/ plant problems - just trying to dial in the medium and see if thats another step to take to achieving success (1GPW)



Nice plant silver - but I'd like to disagree. Not all plants get the fall colors - Some times too much Nitrogen - or hte cold will help - but its mostly genetics.

to get any pretty colors on Green Crack - you gotta run her 8 weeks and drop the night temps by a whole 10 degrees at the least.

You are both great growers - who cares

In regards to great white specifically, its overpriced. Go to ogbiowar.com and buy the bennies that capsulator sells. Much more concentrated and less expensive. They are definitely beneficial even with synthetic nutes. The thing is that synthetic nutes inhibit root growth vs. Organic nutes, so there is less root mass for the microbes to colonize. You'll need to apply the teas more frequently than you would with an organic garden.

I agree with you.. some plants display fall colors more readily than others. Colors are minerals left behind in the leaf... They contribute to flavor. A well flushed plant turns yellow, after most of the minerals have been removed. Not everything gets flushed out in colder temps... Sure does look pretty though.

you flush your organic beds bobble?

No flushing. I stop foliar sprays after 5 weeks. After that the plants get plain water for their feeds.

LyryC:

Interesting. Peat and Perilite is a professionals medium.

But since Peat is made from Sphagnum Moss - It is on the decline in popularity - use and availability. We have pretty much farmed up most of the Peat we can and in doing so have been harming mother earth.

Its a shame such a great medium will soon cease to exist - but I would like to pose a question for you pros to consider.

Why not combine the two? Coco Coir and Peat? Or are they arch enemies to thee end and contradict one another? Of course with perilite added to the mix - and if it were me - growstones also.

Happy Gardening brothers curious to learn!

bobblehead:

The trouble with coco is its high CEC. You have to charge the coco before it will make nutrients available to the plant. That's fine and dandy with synthetic nutes... But with organics which are slower to release, and I'm not talking bottled stuff either, its difficult to make the nutrients plant available and charge the medium. Soil tests could be used to balance the CEC, but its a lot more difficult than using peat. I used 12 bales of peat to fill my beds... And I won't have to fill them again in my growing career.

Are we about to run out of peat bogs? Cause my grow shop has lots of promix in stock... I understand its not the most eco-friendly, but I don't see a shortage.

Hi, LyryC. Hi, bobblehead.

Interesting data on peat. Thanks for sharing.

We have experimented with peat and coco coir in SRBGB`s. Peat tended to retain moisture for an extended period, without an effective means to `dry` it out, especially underneath the primary root mass in the center of the medium. We would periodically let a given unit `dry` out on the surface and then dig out the root mass and examine the media`s saturation level to review its properties under those conditions. Invariably, there would be pockets, or more appropriately, a pocket of saturated moisture in the center of the media mass. We experienced a similar phenomenon with coco coir. Both conditions could be managed by aerating the base medium with aerating amendments and simply watering less. Even then, it might still be challenging to maintain a balanced dispersal of that moisture within the medium. The top (surface) might tend to dry out much faster than the center of the media. Without extracting samples of the media from the approximate center of the substrate, it might be diffucult to accurately measure the `wetness` of the media.

We have experimented with an `organic` water only regime with coco coir. It can be done, with proper consideration for the inherent calcium, potassium and other compounds held within the coir. Any number of amendments could be mixed into the media. We included various foodstuffs and, or, controlled release fertilizers. The more inputs, the more variables to manage. Ultimately, we found that mycorrhizae and molasses were adequate sources of biological activity and raw organic nutrients to sustain health of the the specimen.

There are various forms of mycorrhizae that could be employed, from powders to liquids. We found the simplest were solid tabs that could be crumbled into a powder-like form and dispersed throughout the coir. The tabs might also contain a slow release fertilizer (we do not currently have the exact NPK`s to post), which as a standalone could also sustain a specimen for an entire season. That would limit the inputs to 1.

We tried various forms of molasses, both liquid and dry. Either might work well. With dry molasses, the gardener could disperse it and the mycorrhizae into the coco coir, or other medium prior to sowing the specimen, then simply apply water only for the duration of the season. With liquid molasses, roughly a teaspoon per gallon of water - or less - could sustain a given specimen, in general, throughout and entire season. That would be only 2 total inputs.

There are also methods to calculate the approximate NPK-Mg-S of molasses, based on the `Nutrition Facts` label, if the gardener wanted to chart approximately how much each element would be contained in a soultion of water.

Even if the regime requirement was 100% organic, for sustainability and re-usability, we would still probably prefer pumice in various grades to peat or coco coir. We found inert rocks (see #165) simpler to re-use, manage the pH, even saturation (moisture) dispersal, et. al, than coco coir or peat or soil.

There are perhaps some gardeners that have found methods of re-using coco coir, peat or soil immediately or continuously, managing the aerobic-to-anaerobic balance within the substrate. It would appear to be certainly achievable. Such a task might require a broader conception of the garden than only the plants or trees, which may be a very fundamental, or, universal gardening principle.

We would only post that there might be many possible options, each of which may be viable for that gardener. Pre-amending coco coir, peat or soil and supplying only water might be possible; implementing remediation of and recycling the process might be an entire task unto itself, irrepsective of the seasons` progress or state. Organic gardening with inert rocks might also be possible.

With our experiments using SRBGB`s, we tried a fair amount of novel or hybrid approaches, and during the process developed a rough sketch of the drain to no waste method, which we found to be implementable with nearly any medium.

There may be any number of possible inputs, but the fewer the simpler it might be for the gardener to accurately measure the state of any input at any point on the flow chart. The more inputs, the more possible combinations of outputs, or expressions of conditions to calculate, measure or simply consider.

--


bobblehead:

Hey D remember that chat where I said I did have my coco dialed...



Mister_D:

Not the best example, but it will give you an idea of what I mean.


Hi, Mister_D. Hi, bobblehead.

Will not the same:same thread perhaps draw more defined comparisons on the canvases using the same brushes, with the gardeners` own selection of input colors?

It might be difficult to distinguish between expressions when they may appear to be different items, having their own distinct qualities or characteristics, at different points of progression relative to each other on a linear time graph.

Kind regards,
/SRGB/

Yes comparing varying cultivars fom varying environments isn't a fair comparison.... I'm just playing D's game... "No, my dick is bigger!" Lol

As for what is organic/inorganic and substrate preference...

Forms of N vary drastically between the two. In an organic approach, the N balance is generally 80/20 NH4/NO3. The ratio is inverted with synthetic nutrients. NO3 encourages stretching, foliage growth, and inhibits root growth. In organic farming, the farmer is relying on microbes to make nutrients available to the plants. The microbes have a symbiotic relationship with the roots. In order to make more nutrients available, the grower needs a healthy root mass to increase the number of microbes that make nutrients available to those roots. Inhibiting root growth with nitrate fertilizers is counterintuitive to this method. No-till farms are also shown to have higher microbial populations than farms that are tilled regularly.

My goal is to culture as many microbes as I can to make nutrients available to the plants and maintain my plants in good health through competitive inhibition. No-till peat beds are the best option for this that I have come across in my research.

 

[calientecarlos]

Great thread Bobblehead! I got into organics bc i'm a cheap ass n tend to be lazy. It has worked out great! Gonna buy me a refracto n get even more official meow. Thx for kickin all the k'nowledge!

 

[bobblehead]

Hey guys I could use some help.

My Marey tankless water heater has stopped firing, and so I don't have a CO2 generator. The wiring is good, the pump is good, water temperature doesn't seem to make a difference...

Does anyone know how to go about rewiring the burner? I really don't care about the water activated feature. There has to be a way that the CO2 controller can just ignite the burner instead of activating a water pump.

Thanks!

 

[dank.frank]

"Fall" colors can be expressed WITHOUT flushing at all....in fact, when a plant is grown properly and allowed to mature fully - it will and does enter into senescence...without any need to deplete the medium or the plant of nutrients...

Having a plant express DEFICIENCY - is NOT the same as having a plant express itself, from age and proper time...

Cold temps bring about coloration as well, without having anything to do with deficiency brought on by flushing or senescence...

My point being, there are MANY different factors that contribute to how cannabis expresses color - and to simply state "a proper flush" is a very incomplete analysis.

"Cellular pH being genetically regulated, each strain has its own unique combination of chlorophyll and carotenoids and potential for anthocyanins production."



dank.Frank

 

[LyryC]

So much love in this thread

Thanks Bobble - Silver - DF - and SGP

 

[SRGB]

bobblehead:

My goal is to culture as many microbes as I can to make nutrients available to the plants


Hi, bobblehead.

Which specific `microbes`?

What is the minimum input requirement?

What is the maximum input requirement?

What is the point of diminishing returns after `x` input?

How is the efficacy of the requirement measured?

Which `microbes` consuming which `microbes` produce `x` amount of NH4? P, K, Mg, S, et al.?

Have you employed the same practice of microbe input and derivation of nutrients with the specimen in the fired glass medium?

If the relationship between plant or tree roots and `microbes` is symbiotic, will the `microbes`, in general, find and populate the rhizophere or root zone independently, without affirmative gardener input, to the density required for root or specimen health?

From what we could gather, roots exchange ions (electrical charges) to absorb those essential elements present in a soluble form into their tissue; releasing one or more internal charges out into the surrounding root zone environment when the ionic exchange occurs.

How do microbes react to, or interact with, the released electrical charges from the roots?

What methods does the gardener have to measure the effectiveness of a given population of microbes in a given volume of root filled substrate?

For example, given 1 gallons of substrate filled with roots, what is the ideal population of `x micro organism` to `y micro organism` to `z micro organism`, and what would be the approximate accumulated sum of each element, or electrical charge, derived from the activity of that microbe population at substrate pH ranges (solubility) from `a.a` pH to `z.z` pH?

Interesting topic. There might be a fair number of variables in even base organic chemistry having `x` variables. If the variables can be calculated accurately, perhaps the gardener might be able to tailor a regime that inputs only the required variables to produce the desired result, with methods available to chart the efficacy of a particular approach at any given point on the flow chart.

Kind regards,
/SRGB/

 

[Mister_D]

"Fall" colors can be expressed WITHOUT flushing at all....in fact, when a plant is grown properly and allowed to mature fully - it will and does enter into senescence...without any need to deplete the medium or the plant of nutrients...

Having a plant express DEFICIENCY - is NOT the same as having a plant express itself, from age and proper time...

Cold temps bring about coloration as well, without having anything to do with deficiency brought on by flushing or senescence...

My point being, there are MANY different factors that contribute to how cannabis expresses color - and to simply state "a proper flush" is a very incomplete analysis.

"Cellular pH being genetically regulated, each strain has its own unique combination of chlorophyll and carotenoids and potential for anthocyanins production."



dank.Frank

Didn't say a proper flush is the only way to achieve fall colors. You are correct it's not a requirement to use/remove all/most of the nutes to achieve fall colors. However this is only true when using organics. Continue to feed a plant chem nutes at normal levels and it will stay green until you stop feeding. In nature plants know via various triggers to stop exuding sugars to exchange for nutrients towards to the end of their lives, thus naturally accomplishing the same thing flushing does with chem nutes. To what degree and which colors show is genetically dependent, but it remains true all plants will show colors when fed and flushed correctly. Doesn't matter if it's accomplished via the natural cycle or from human interaction. Merely different techniques being used to achieve the same goal. Of course cold and other things/methods will also cause a break down of chlorophyll, bringing on the color, but I'm fairly sure nobody here is interested in using techniques that effect growth in a negative way.

 

[Mister_D]

Oh so like this DGSC#3 before I ditched coco 100% and switched to peat.
View Image
View Image

Yes those look much better Now remind me again why you think peat is better?

 

[dank.frank]

Well, you are absolutely correct those things apply directly to organics - as that is how I grow - and how I tend to further educate myself in regards to my garden.

However, the statements are fully accurate - regardless if you feed chem or grow in water only organics or even using organics and feed teas and foliars, etc.

My point was to simply state - that it is important to understand the fullness of what causes colors - rather than to simply say a well flushed plants shows colors - that does not equate to a plant being grown to it's fullest potential...

Personally - I think ANY sort of additional feedings - organic teas or chem nutes or foliar, etc - ANY additional feeding alterations outside of what the plant will and does decide to take from the soil on its own - produces a variation in the natural expression of the plant. I started focusing in on water only organics primarily because I wanted to begin selecting the very best phenos out of seed stock possible - NOT the one that appeared to be the best because I had essentially shot them full of steroids (fully ionized nutrients) the roots had no choice in up-taking and processing....creating a need to flush them out.

When EVERYTHING the plant could possibly need is already in the soil - the plant, as you said, will take from the soil as it needs, and when the time comes, will automatically enter into a phase where it stops feeding and then eventually dies - your truest expression of what the plant is - is then found - and when you pick a keeper, it is TRULY the best pheno you had available to you...not the one that did best on such and such nutrients or such and such a medium.

And this isn't poking at anyone person - this is just what I have learned via my own personal experiences over the years.



dank.Frank

 

[bobblehead]

bobblehead:

My goal is to culture as many microbes as I can to make nutrients available to the plants


Hi, bobblehead.

Which specific `microbes`?

NUTE PACK:


The Nute pack is an ideal way to boost your plants ability to do what it does best: grow and flower. With the proper application, you will see a noticeable difference in growth, yield and overall vigor.

-Nitrogen fixers, which convert nitrogen gas in to usable nitrate. Nitrogen fixers also will increase plant growth as they produce vitamins, auxins, and gibberllins. Nitrogen fixers give a boost to seedlings germination and overall yield.

-Phosphate solubilizers, which will dissolve fixed tricalcium phosphate in to the usable form monocalcium phosphate. These little guys also produce organic acids (citric acid, lactic acid), hormones, and enzymes which will help in nutrient uptake and general plant vigor.

-Potash mobilizers,that will seek out Potash near the root zone and bring it to the roots of the plant. It is great for low K soil, or coco, since coco is known to "hold" K.


-Mycorrhizae. This product has 100 spore colonies of 9 different endo mycorrhizae



ROOT PACK:

The root pack is a proprietary blend of over 20 different different species of beneficial fungi and bacteria. The root pack is designed to promote plant health by boosting immune systems, shoot and root growth, flower production, and the overall well being of your plants! The root pack includes (but is certainly not limited to) the following species:

-Pseudomonas flourescens: This is a saprophyte that creates colonies in water, soil, and on plant tissue. It will suppress plant diseases by acting as a systemic (a unique ability). Once it enters the vascular system of the plant, it actually produces antibiotics which prevent fungal and bacterial diseases from taking hold.

-Bacillus: Bacillus is best applied to young plants and seedlings, so that it can take hold and colonize on the developing root system. Here, it will offer protection by limiting the growth of fungal organisms like fusarium.
This bacteria alsosupresses other fungi and bacteria that cause scab, powdery mildew, sour rot, downy mildew, and early leaf spot, early blight, late blight, bacterial spot, and walnut blight diseases.

-Trichoderma: Trichoderma is a beneficial fungus, that will seek and destroy other harmful fungi in the soil/media. The presence of trichoderma will also cause the plant to activate its own SAR (systemic acquired resistance), which in turn causes the plant to boost its own immune system.



FOLIAR PACK:

The foliar pack is designed as a 100% safe, non chemical spray for Environmental stresses.

People say that it has fixed problems associated with root aphids, broad mites, aphids, thrips, harmful nematodes, spider mites, fungus gnats, whitefly, and caterpillars.

All three packs were designed with 100% compatibility in mind. They are meant to work together, to help your plant be all the it can be.

What is the minimum input requirement?
What is the maximum input requirement?
What is the point of diminishing returns after `x` input?
How is the efficacy of the requirement measured?
Which `microbes` consuming which `microbes` produce `x` amount of NH4? P, K, Mg, S, et al.?

Lots of good questions, but I don't have an solid answers. There is no need for minimum and maximum inputs. I don't have the equipment yet to determine a point of diminishing return or measure the efficacy of the microbial tea applications. The roots can sustain x amount of microbes. The level changes with the amount of roots produced. Nutrients made plant available can be measured with a soil test. I believe I can pay to have my microbial populations tested as well. I haven't got to that point yet.

Have you employed the same practice of microbe input and derivation of nutrients with the specimen in the fired glass medium?

No I haven't tried the microbe input with the fired glass product, but I have in perlite. There was without a doubt a beneficial response. The microbial tea also contains EWC and Alfalfa, so some of my organic nutrients have been applied to plants grown in perlite fed a mostly synthetic nutrient regime. The difference is that my peat beds have dry amendments for the microbes being applied to consume. I also have arthropods and worms in my beds that play a role in the soil food web that couldn't be sustained in fired glass.

If the relationship between plant or tree roots and `microbes` is symbiotic, will the `microbes`, in general, find and populate the rhizophere or root zone independently, without affirmative gardener input, to the density required for root or specimen health?

Yes. It doesn't matter if you apply the soil microbes as a foliar spray or you apply them as a root drench. The microbes will migrate to thee roots.

From what we could gather, roots exchange ions (electrical charges) to absorb those essential elements present in a soluble form into their tissue; releasing one or more internal charges out into the surrounding root zone environment when the ionic exchange occurs.

How do microbes react to, or interact with, the released electrical charges from the roots?

I don't know about the exchange of electrical charges... but at night the plants send the starches produced during the day into the stems and roots to be stored long term, and some of the starches sent to the roots are sacrificed as root exudate to feed the microbes. As the plant produces more starch, more exudate is released and larger microbial colonies can be sustained.

What methods does the gardener have to measure the effectiveness of a given population of microbes in a given volume of root filled substrate?

One day I would like to buy a microscope. I'll probably make agar plates and do some colony counts and see what I can isolate as well. I just don't have the spare cash to invest in the equipment right now. I'll also be relying on soil tests.

For example, given 1 gallons of substrate filled with roots, what is the ideal population of `x micro organism` to `y micro organism` to `z micro organism`, and what would be the approximate accumulated sum of each element, or electrical charge, derived from the activity of that microbe population at substrate pH ranges (solubility) from `a.a` pH to `z.z` pH?

Honestly I don't measure this, because the plants should manage it on their own. Ideally all I will have to do is water them and apply some foliar sprays. After a few grows I will try and stop inoculating microbe teas derived from all 3 of the ogbiowar packs. Once the beds are fully colonized, there won't be space for additional inputs. The microbial populations will be self sustaining. Additional inputs won't be of any benefit because all available resources will already be getting consumed. In theory anyway. pH should self regulate at some point with enough Ca in the soil... but I'm keeping an eye on it to be safe.

Interesting topic. There might be a fair number of variables in even base organic chemistry having `x` variables. If the variables can be calculated accurately, perhaps the gardener might be able to tailor a regime that inputs only the required variables to produce the desired result, with methods available to chart the efficacy of a particular approach at any given point on the flow chart.

Kind regards,
/SRGB/

Initially there is some work for the gardener... inputs to be tailored... but once everything is going, its supposed to be self sustaining. Soil tests let the gardener know what inputs are needed. The plant controls the release of nutrients be either sustaining the microbes or letting them die.

 

[bobblehead]

What was I thinking ditching a medium that makes balancing Ca, Mg, N, K, and P difficult?

@ 2.5 weeks
Death Star

Golden Goat

 

[bobblehead]

Straw DD- not so much these, but remember, they were over-watered when I transplanted.

Vert room @ 3 weeks.

So yeah I was pretty much thinking I could grow some of the best crops I've ever produced if I did what was considered by most the industry standard... Coco is ok, i'm not the one calling it horrible stuff. I just thought it sucked for keeping my plants healthy. I was chasing Ca issues all the time.

The best buds I've ever smoked were grown organically... So if I'm going to produce anything close, I figure I had better try to use the same method. Its even more difficult to balance coco's CEC with slow release ferts. I'm sure it can be done, but I'm not trying to experiment.

 

[silver hawaiian]

That middle bed looks bananas

The best buds I've ever smoked were grown organically...

 

[Mister_D]

I just thought it sucked for keeping my plants healthy. I was chasing Ca issues all the time.

Starting to sound like a broken record here, but like I've been saying your nute recipe wasn't 100% dialed. I'm sure you notice my plants never seem to be deficient in anything. I don't find myself constantly chasing nute problems. Make it a point to understand what the plant wants, and what the media requires to deliver what the plant wants and your golden. Coco is no different from any other media in this respect. All have special needs that have to fulfilled in order to reach that medias full potential. All about dialage my man .

The best buds I've ever smoked were grown organically... So if I'm going to produce anything close, I figure I had better try to use the same method. Its even more difficult to balance coco's CEC with slow release ferts. I'm sure it can be done, but I'm not trying to experiment.

Oh contraire, experimenting is exactly what you are doing . It's all good though, do what you think is best. One day maybe you'll revist and actually dial coco 100%. On that day, you'll say to yourself, damn it ole D was right Coco does grow bigger buds faster than peat

Strawberry DD excluded the beds look excellent bro

 

[otis33]

bitchin canopy bobbles!

 

[bobblehead]

Thanks for the tips guys... I like to think I use evidence based practice vs. experimentation... but sure, all of my grows are an ongoing experiment.

Some additional notes since I have a minute:

Brix is going up, but I haven't had the time to measure brix before spraying, and again 2hs after. The other thing I've noticed between this grow and the last is that soil moisture plays a role in brix. The more moist the soil, the lower the brix. Temperature also plays a role, but temps are fairly constant. I need to quit being so lazy and start a notebook with soil moisture levels, brix, temps, days flowering, etc... Anyway, I'm just measuring brix between sprays as time permits. As long as its moving upward, I'm good.

My CO2 genny/water heater took a shit, and its probably because I was using a/c condensate to feed it. I think the radiator is plugged and I'm going to try and run some vinegar through it to clear it out. I ordered a new genny, only $100, and I'll hook it up to a clean res. I read that its actually best to use cold tap water and run it to waste. I might go ahead and start running the water to waste from now on.

My last grow, quality suffered and it appears as if it was heat stress. I bought an infrared/tympanic thermometer to measure canopy temps. My big room was a little high but I just dropped the a/c 2F and canopy temps are 86F or lower. The vert room is another story. I don't have fan blowing right under the lamps, and some of the leaf temps are 100F, with 86F room temps and most canopy temps near there. The areas with high temps are adjacent the lamps... So I'm probably switching that room to horizontal after this grow. Its bad enough crawling on hands and knees, I don't need to be crawling over fans as well... I have 2 oscillating 16" wall fans in that room, along with 870cfm of extraction, for 2400w. I might drop a 24kbtu a/c in that room and seal it up.

I think that's all for now. Still haven't hooked up the blumats. I pay more attention when i have to water the beds myself, and its not so bad with a pump and hose. I only water every 2-3 days right now.

 

[Mister_D]

Definitely diging your experiments or rather "evidence based practice" with the brix meter. Might have to grab one of those myself in the near future. Rather curious to see the difference between the same strains in the big organic room and the chem remote grow. You should grab a notebook and start making notes, ya know how I love to steal your ideas and discoveries . Very interesting about brix being higher with a drier media too, not something I would have ever thought of. Any idea why this might be?

 

[bobblehead]

Definitely diging your experiments or rather "evidence based practice" with the brix meter. Might have to grab one of those myself in the near future. Rather curious to see the difference between the same strains in the big organic room and the chem remote grow. You should grab a notebook and start making notes, ya know how I love to steal your ideas and discoveries . Very interesting about brix being higher with a drier media too, not something I would have ever thought of. Any idea why this might be?

Chances are good you'll see a lower brix in your chem room because nitrate fertilizers pull lots of water into the plant. Part of the increased growth in plants fed synthetic ferts is water weight.

The brix moving with soil moisture is as simple as osmosis really. Leaf sugars are suspended in water, a lot like human plasma which consists mostly of water. An over-hydrated plant will have dilute leaf sugars, and a lower brix. A slightly dehydrated plant would have a higher concentration of leaf sugars and less water.

Over-watering and dehydration will both have a negative impact on brix... But you can also see normal fluctuation depending on soil moisture levels.

PS- you can also read Ca levels by seeing if the line in the refractometer is fuzzy or not, and just how fuzzy it appears. A clear line indicates low Ca levels. Very helpful in that coco stuff you use.