Droughting and its medicinal effects in cannabis

[Krissi Carbone]

Thank you so much! I look forward to learning more about this growing technique!

You're quite welcome Mack! Happy to hear!

 

[Krissi Carbone]

@Maritimer 's very own droughted and massive ladies

Seeing is believing

 

[Maritimer]

going hollywood hehe

 

[Krissi Carbone]

going hollywood hehe

Like Tom Selleck in the 80s

 

[Cactusreefer]

I must apologize for asking redundant questions here...
1st, Krissi get well soon! I just got over the rona myself. Still cant smell or taste.
I just got home and had a lot of catching up here. For review... we are after 50% wilt, correct? And study has shown at 7 weeks, it takes 11 days to achieve. I guess what Im asking is does it matter the quality of time? Is it something that works better with a low and slow approach to 50%(11 days) or quickly [say 3-4 days). I would imagine different mediums respond differently. But drought wilt is response to moisture, so does length of time really matter so long as you achieve that 50% LWA. Im guessing nothing good happens fast...sorry for repeat questions. Appreciate this thread!

 

[Krissi Carbone]

I must apologize for asking redundant questions here...
1st, Krissi get well soon! I just got over the rona myself. Still cant smell or taste.
I just got home and had a lot of catching up here. For review... we are after 50% wilt, correct? And study has shown at 7 weeks, it takes 11 days to achieve. I guess what Im asking is does it matter the quality of time? Is it something that works better with a low and slow approach to 50%(11 days) or quickly [say 3-4 days). I would imagine different mediums respond differently. But drought wilt is response to moisture, so does length of time really matter so long as you achieve that 50% LWA. Im guessing nothing good happens fast...sorry for repeat questions. Appreciate this thread!

We are under the assumption that the amount of time varies on different factors so the 11 days or as some like to say the 9th day when things are supposed to 'start happening' is not even across the board. Many factors play in. This is a controlled drought but that was also a controlled test keep in mind. But yes, ultimately the goal is for the plant to hit the 50% past turgid mark for LWA. The droughting time of the medium, the timeline as to when the 'magic' starts happening and all of those variables are noteworthy and make grounds for further discussion. As this wasn't done on multiple playing fields, we are all in the process of finding out for ourselves. I can attest personally and I know others can as well, that it does not necessarily take the full 11 or even 9 for the effects of the drought to be noticeable. I will have further digging into all these questions tonight or tomorrow. I hope that helps as all.

 

[Joe Brewster]

In nature cannabis being a weed, grows tall or bushy to block out other weeds .
In drought conditions it has the ability to get water from the dew in the mornings

That is why it has such big roots just below the soil surface
So I'm sure room humidity plays a big part in drought


example of roots near surface

Superstinky 420.jpg

• Joe Brewster
• Apr 20, 2020

 

[Maritimer]

Conclusions of Caplan's thesis 117 pages long or so
Caplan
Cannabinoid concentration and yield in the dry floral material of cannabis exposed to drought stress at week seven in the flowering stage. T
Conclusions
This study suggested that controlled drought stress can increase the concentration of major cannabinoids THCA, CBDA and the yield of THCA, CBDA, THC, and CBD in chemovar II cannabis without reducing dry floral weight (yield) and irrespective of decreased Pn. These results were achieved by gradually drying the substrate over eleven days until plant WP reached around -1.5 MPa during week seven in the flowering stage. Comparable results can be expected using leaf wilting as a drought stress indicator with fertigation triggered at a leaf angle 50% higher than in its turgid state. This method for administering drought-stress and the results of this study should be applicable for similar varieties of chemovar II cannabis; however, other chemovars or varieties may respond differently.
Yield in the control was 178 ± 9.4 g·m-2 and was 232 ± 18.5 g·m-2 in the drought treatment but yield did not differ statistically between the two treatments (P = 0.06; n = 3). The moisture content of the dried and cured floral material was 8 ± 0.1 % in the control, 11% lower than that in the drought treatment, at 9 ± 0.1 % (P = 0.01; n = 3). Henceforward, the floral dry weight and cannabinoid contents are corrected to zero percent moisture.
Of the analyzed cannabinoids, all were detected in at least one sample, these included: THC, THCA, CBD, CBDA, CBG, CBGA, and CBN. In the drought treatment, only one sample had a detectable concentration of CBG and CBN, and in the control there were no samples with detectable CBN; therefore, comparisons could not be made for these cannabinoids, and the means for CBN were not presented.
The drought treatment elicited a 12% increase in THCA concentration and a 13% increase in CBDA concentration but had no effect on the concentrations of the other detected cannabinoids Drought had substantial effects on cannabinoid yield, expressed as grams of cannabinoid from floral material per unit growing area (g·m-2). In the drought treatment, THC yield was 50% higher, THCA yield was 43% higher, CBD yield was 67% higher, and CBDA yield was 47% higher than in the control

 

[iffey]

 

[iffey]

Some how (I'm new at adding pics here) the words didnt go with the pics

FYI Krissi: Just another style of growing worth knowing about

I grow in PassivePlantKiller (PPK). I've done searches here on : PPK (I get allot of Purple Pain Killer) but no return on my growing style or for Passive Plant Killer.. So I guess answering questions of it may be an unknown for you. Thats ok with me..
Media = MVP.. basically clay chips very similar to old cat litter (not used cat litter

). They are top fed and are also wick fed from below as required, if required. Any way, I have cut feeding today & drained the lower rez as it would start feeding as soon or soon after watering stops. The strain is G13 (my second run) at day 60 bloom breeder suggests 63 days I;m shooting for 75. I'll adjust the cut as necessary, maybe 15 days drought.. we'll see..

 

[Krissi Carbone]

@nivek the realistic difference you can expect to see given the 20% increase noted in the study would be more than you would think. Upwards further from your immediate assumption at 10%. Although we have not tested this theory in hempy, the plant dynamics would lead us to believe that with a prolonged and/or increased drought, we would still be able to reap the benefits as the plant, above all is kicking itself into over drive to protect its thought to be babies locked in its flowers

@Azimuth we are all agreeable that the stress period of drought between hempy and soil is very different. We are working to find a candidate to offer us assistance in completing a drought journal for this particular medium as we have no account of an attempted drought using this medium. After conversation, we would assume that within 3-5 days would be enough time to elicit the response we are looking for. I prefaced this next comment with the aforementioned as you had a question if anything actually happens before that 9th day. The answer is YES. As soon as the GNR (Genetic Regulatory Network) and its sensory cells begin noticing a moisture level decrease, the sounders go on. Although it may not be a visible change early on in the first few days, there is a lot happening as the cannabis is trying to protect what it thinks is its offspring hidden in its flower. It will do everything in its power to direct any and all focuses to the preservation of those seeds it thinks are in there. The best way our plants can protect their "young" is through increased essential oil production-to the plant, in essence, it is putting its own version of a force field around its children. So to touch upon is it gradual and then it kicks into over drive, yes and no. The process is already in motion, the wheels are already turning and the cannabinoid profiles are changing and increasing from the very second that GNR and those sensory cells realize they aren't getting their normal amount of moisture.

@greenjeans Hydroton and perlite are obviously different. In our opinion, perlite holds water better than hydroton as those clay pebbles don't hold water well. This drought was done in a hydroton environment by a well known member here in @Rexer. We are working to find a grower to do a documented drought for us via perlite.

Noting here also that yes, there is a downside to going under the LWA percentage of 50%. We want the plant to recover we are stressing her, highly, but not trying to kill her. Fine line that is easily expressed and controlled via LWA.

@MackMcMacMac everything we are asking our plants to do during this stress is a natural reaction that they do anyway. The plants know their life cycle through their internal clock and through their environmental cues. A shorter finishing strain like the one you have should have no issues if you were to implement the drought beginning at week 6 rather than week 7. However, it is up to you whether you want to give her time to recover and plump up after her drought or let her know she has had enough and pull her. The time table is an approximation of when to start given a number of variables. If you started at week 7 you could run her through the end of drought and pull her immediately or begin at week 6 and let her plump up for another week when she is finished. Both results, because of the way the GNR system works as previously noted, will elicit the same response.

@Renaissance Man yes protractors are a thing. Over time you won't need to use one any more as you get a feel of your girls. You will get a feel of the drought yourself and in that time, you will be more connected to your girls and be able to read them better. Rex has an app I believe but I like the old school methods. Yes, trichome development has many variables yet their development in itself and the reason for it does not. As mentioned earlier, the ONLY goal of our plant is to procreate. It's ONLY purpose is to make babies. It's MAIN way and ONLY way it knows to protect its children is through ramping up essential oil production to cover the flower which holds its thought to be babies (seeds). These plants have a special survival coding in their DNA that is extremely strong. It uses all of its energy in a drought to take care of itself and focus on trichomes. The sensory cells talk to the plant and the ABA level then rises which drives the plant into H2O retention mode. Trichome production and development goes way back to its early vegetative stage. There is a "pubescent " period between vegetative and early flower where the plant begins to gain structural integrity and foliar mass; in this time, the plant is producing its reproductive responsibilities as its GRN changes. At this juncture, the homeostasis of different hormones is in effect to accommodate for the change in grow cycles. It is at early flower (1st 2-3 weeks) that gonads become fully developed and the trichomes are in full gear development mode as this is the main part of the reproductive responsibility in the plant's DNA

@iffey @PlanetJ in regards to pot size and mediums-yes, they are both contributing factors in the duration of a drought. Obviously a larger potted and more water holding medium would allow for the ease of accomplishing the full 11 day drought however, it does not warrant that a drought of shorter time given a smaller pot size and less moisture retention medium would neglect to give you the same or comparable droughting results. Hermie possibilities of course are elevated in times of severe stress. The best thing I could tell you is I haven't had one hermie on me yet. Maritimer has but he has also done this quite a few more times than I. His best advice was to just be honed into your girls and be vigilant in checking on them. For a lot of you harvest time and how to figure it out is a question. Go ahead and just toss that thought aside. We don't need to be exact here guys and gals. Around week 7 give or take, begin your drought. Whether you choose to keep your girl going for another week or few days or hault her in her tracks when the drought is done and pull her to harvest is up to you. If you feel the plant could bulk up or plump up further, let her do her thing. Don't be so concerned with trying to figure out when you should harvest her when trying to decide when to begin your drought. Personally, my plants like being back for a week-ish after their drought. I have not pulled one yet directly from drought to harvest. Would a 75% reduction in water provide the same results. Again, not tested, but it theory, yes. As we touched on earlier, the plant has sensory cells which relay information to the hormones telling the plant hey, things are changing over here, again it will do EVERYTHING to protect the babies it thinks it has in those buds. So as soon as that moisture level is changed, the GNR starts doing its thing, telling the girls to increase that essential oil production-giving us those extra trichomes. A PPK is new to me, I'm learning from you as we go! As for 'clogged wick' or root issues overall, at this point, your plant is not dependent on the preservation of its roots to survive. The roots are not as fragile to oxygen as we have been led to believe. It's focus at this point in development is to produce more essential oils. Tying in RH here also, in that, her stomata is now closed because of the drought, she will not be taking in any more moisture. I touched upon transpiration and pressure early in this thread (I went into the science for a reason). At the point your girls are at when droughting, their water volume and pressure is maxed out and as such, she shuts down trying to take in any moisture. What she has in her now, think of it as steam building up in a pot with no where to go (her stomata like I said is closed, that is where she would normally take in and/or release that pressure)-well that moisture in there is staying and because of that, this is why droughting will NOT KILL your root zone (contrary to popular belief without knowing the science-see I told you this was important to know 1st)

In closing, it is easier to think of this whole system when you break down your plant into its life cycles-Seedling, vegetative, early flower, flower and late flower. The drought is timed in a way to coincide with LATE FLOWER, which is 2-6 weeks strain dependent. This is when the floral mass, seed production, essential oil production, and trichome development (that and the oil development go hand in hand) are the plants primary responsibilities.

If anyone else wants to expand, elaborate, question, discuss, comment-the floor is always yours. Thanks to everyone for joining us, for keeping an open mind, and wanting to learn more!

Salute

 

[Krissi Carbone]

Some how (I'm new at adding pics here) the words didnt go with the pics

FYI Krissi: Just another style of growing worth knowing about

I grow in PassivePlantKiller (PPK). I've done searches here on : PPK (I get allot of Purple Pain Killer) but no return on my growing style or for Passive Plant Killer.. So I guess answering questions of it may be an unknown for you. Thats ok with me..
Media = MVP.. basically clay chips very similar to old cat litter (not used cat litter

). They are top fed and are also wick fed from below as required, if required. Any way, I have cut feeding today & drained the lower rez as it would start feeding as soon or soon after watering stops. The strain is G13 (my second run) at day 60 bloom breeder suggests 63 days I;m shooting for 75. I'll adjust the cut as necessary, maybe 15 days drought.. we'll see..

This sounds so interesting and where did you hear about that to begin with @iffey ?! We were discussing that last night but I had no idea what PPK was!!! Lol considering what you just told me, I think you have a good idea to implement this into your system. It's all trial and error man, we wouldn't have learned how to do anything until we tried it. You know as well as I do that those breeder specs are iffy, lol no pun intended. Don't be too concerned with the time, go by the LWA to determine when to stop it. Feel for your girl if you may.....I'm excited to see what you come up with. If you get it going, would you be interested at all in a future drought, documenting it for us as we will be with other mediums? That way we can enlighten 420 with your technique and your ability to drought while using it

 

[Azimuth]

Interesting.

So that then suggests that there is not much happening during those first 9 days other than drying out the media, and that the magic happens subsequently in the following two days(ish).

So really the timeline should not be a generic Week 7, but rather should be counting back from expected harvest date a few days to allow for rehydration if you want, subtracting two more days for the magic and then subtracting however many days you need to dry out your media.

So, rather than saying Week 7, it's better to count backwards.

That is assuming I am interpreting your above response correctly.

Week 7 is strain and media dependent and is really only relevant to the combination used in the original study.

So, sativa's will be much longer than week 7, and Hempy and hydro will presumably have a much shorter dry out period.

 

[Krissi Carbone]

Interesting.

So that then suggests that there is not much happening during those first 9 days other than drying out the media, and that the magic happens subsequently in the following two days(ish).

No. To only this comment, basically yes to the rest! Much is happening during those first 9 days as noted the second the plant realizes it isn't getting what it usually does, the GNR network and those sensory cells tell the plant IMMEDIATELY to start ramping up ABA and in that, the cannabinoid profiles are already on the rise

So really the timeline should not be a generic Week 7, but rather should be counting back from expected harvest date a few days to allow for rehydration if you want, subtracting two more days for the magic and then subtracting however many days you need to dry out your media.

I wouldn't even put it in a magic happens during this time thing...I believe the the study suggests or at least presents itself as such, only because there was no work done during that time to properly note what was going on in the plant at that juncture-making it seem as if nothing beneficial was happening prior and that there was a magic day # if you will. After our talk last night, I am confident that is just an unsubstantiated assumption from our perspective.

So, rather than saying Week 7, it's better to count backwards.

I think that would work better for some

That is assuming I am interpreting your above response correctly.

Week 7 is strain and media dependent and is really only relevant to the combination used in the original study.

Yes you should try to shoot for week 7 but if it doesn't fall that way around your feed schedule, don't mess up your feed schedule to get it started at week 7. It I'd a give or take thing.. not an exaxt number we need to go by.. +/-2, 1 or 2 weeks seems fair

So, sativa's will be much longer than week 7, and Hempy and hydro will presumably have a much shorter dry out period.

Moreso, you can plan on having your sativa around longer after the drought to finish bulking....and yes for the latter

 

[ppm Charlie]

@nivek the realistic difference you can expect to see given the 20% increase noted in the study would be more than you would think. Upwards further from your immediate assumption at 10%. Although we have not tested this theory in hempy, the plant dynamics would lead us to believe that with a prolonged and/or increased drought, we would still be able to reap the benefits as the plant, above all is kicking itself into over drive to protect its thought to be babies locked in its flowers

@Azimuth we are all agreeable that the stress period of drought between hempy and soil is very different. We are working to find a candidate to offer us assistance in completing a drought journal for this particular medium as we have no account of an attempted drought using this medium. After conversation, we would assume that within 3-5 days would be enough time to elicit the response we are looking for. I prefaced this next comment with the aforementioned as you had a question if anything actually happens before that 9th day. The answer is YES. As soon as the GNR (Genetic Regulatory Network) and its sensory cells begin noticing a moisture level decrease, the sounders go on. Although it may not be a visible change early on in the first few days, there is a lot happening as the cannabis is trying to protect what it thinks is its offspring hidden in its flower. It will do everything in its power to direct any and all focuses to the preservation of those seeds it thinks are in there. The best way our plants can protect their "young" is through increased essential oil production-to the plant, in essence, it is putting its own version of a force field around its children. So to touch upon is it gradual and then it kicks into over drive, yes and no. The process is already in motion, the wheels are already turning and the cannabinoid profiles are changing and increasing from the very second that GNR and those sensory cells realize they aren't getting their normal amount of moisture.

@greenjeans Hydroton and perlite are obviously different. In our opinion, perlite holds water better than hydroton as those clay pebbles don't hold water well. This drought was done in a hydroton environment by a well known member here in @Rexer. We are working to find a grower to do a documented drought for us via perlite.

Noting here also that yes, there is a downside to going under the LWA percentage of 50%. We want the plant to recover we are stressing her, highly, but not trying to kill her. Fine line that is easily expressed and controlled via LWA.

@MackMcMacMac everything we are asking our plants to do during this stress is a natural reaction that they do anyway. The plants know their life cycle through their internal clock and through their environmental cues. A shorter finishing strain like the one you have should have no issues if you were to implement the drought beginning at week 6 rather than week 7. However, it is up to you whether you want to give her time to recover and plump up after her drought or let her know she has had enough and pull her. The time table is an approximation of when to start given a number of variables. If you started at week 7 you could run her through the end of drought and pull her immediately or begin at week 6 and let her plump up for another week when she is finished. Both results, because of the way the GNR system works as previously noted, will elicit the same response.

@Renaissance Man yes protractors are a thing. Over time you won't need to use one any more as you get a feel of your girls. You will get a feel of the drought yourself and in that time, you will be more connected to your girls and be able to read them better. Rex has an app I believe but I like the old school methods. Yes, trichome development has many variables yet their development in itself and the reason for it does not. As mentioned earlier, the ONLY goal of our plant is to procreate. It's ONLY purpose is to make babies. It's MAIN way and ONLY way it knows to protect its children is through ramping up essential oil production to cover the flower which holds its thought to be babies (seeds). These plants have a special survival coding in their DNA that is extremely strong. It uses all of its energy in a drought to take care of itself and focus on trichomes. The sensory cells talk to the plant and the ABA level then rises which drives the plant into H2O retention mode. Trichome production and development goes way back to its early vegetative stage. There is a "pubescent " period between vegetative and early flower where the plant begins to gain structural integrity and foliar mass; in this time, the plant is producing its reproductive responsibilities as its GRN changes. At this juncture, the homeostasis of different hormones is in effect to accommodate for the change in grow cycles. It is at early flower (1st 2-3 weeks) that gonads become fully developed and the trichomes are in full gear development mode as this is the main part of the reproductive responsibility in the plant's DNA

@iffey @PlanetJ in regards to pot size and mediums-yes, they are both contributing factors in the duration of a drought. Obviously a larger potted and more water holding medium would allow for the ease of accomplishing the full 11 day drought however, it does not warrant that a drought of shorter time given a smaller pot size and less moisture retention medium would neglect to give you the same or comparable droughting results. Hermie possibilities of course are elevated in times of severe stress. The best thing I could tell you is I haven't had one hermie on me yet. Maritimer has but he has also done this quite a few more times than I. His best advice was to just be honed into your girls and be vigilant in checking on them. For a lot of you harvest time and how to figure it out is a question. Go ahead and just toss that thought aside. We don't need to be exact here guys and gals. Around week 7 give or take, begin your drought. Whether you choose to keep your girl going for another week or few days or hault her in her tracks when the drought is done and pull her to harvest is up to you. If you feel the plant could bulk up or plump up further, let her do her thing. Don't be so concerned with trying to figure out when you should harvest her when trying to decide when to begin your drought. Personally, my plants like being back for a week-ish after their drought. I have not pulled one yet directly from drought to harvest. Would a 75% reduction in water provide the same results. Again, not tested, but it theory, yes. As we touched on earlier, the plant has sensory cells which relay information to the hormones telling the plant hey, things are changing over here, again it will do EVERYTHING to protect the babies it thinks it has in those buds. So as soon as that moisture level is changed, the GNR starts doing its thing, telling the girls to increase that essential oil production-giving us those extra trichomes. A PPK is new to me, I'm learning from you as we go! As for 'clogged wick' or root issues overall, at this point, your plant is not dependent on the preservation of its roots to survive. The roots are not as fragile to oxygen as we have been led to believe. It's focus at this point in development is to produce more essential oils. Tying in RH here also, in that, her stomata is now closed because of the drought, she will not be taking in any more moisture. I touched upon transpiration and pressure early in this thread (I went into the science for a reason). At the point your girls are at when droughting, their water volume and pressure is maxed out and as such, she shuts down trying to take in any moisture. What she has in her now, think of it as steam building up in a pot with no where to go (her stomata like I said is closed, that is where she would normally take in and/or release that pressure)-well that moisture in there is staying and because of that, this is why droughting will NOT KILL your root zone (contrary to popular belief without knowing the science-see I told you this was important to know 1st)

In closing, it is easier to think of this whole system when you break down your plant into its life cycles-Seedling, vegetative, early flower, flower and late flower. The drought is timed in a way to coincide with LATE FLOWER, which is 2-6 weeks strain dependent. This is when the floral mass, seed production, essential oil production, and trichome development (that and the oil development go hand in hand) are the plants primary responsibilities.

If anyone else wants to expand, elaborate, question, discuss, comment-the floor is always yours. Thanks to everyone for joining us, for keeping an open mind, and wanting to learn more!

Salute

A very interesting thread, @Krissi1982 . Such good references and research too. Not ready to begin droughting on my gals yet but I am going to soon. I have so many other things going on, I need to wait and make the-droughting-thing a priority after this harvest in 2-to-4-weeks.

I hope my results are as good as others here. Thank you (et.al.) for all your hard work and collaboration!

 

[Mayne]

Cant lie im sceptical about the idea.
Its like the 24/48 hour darkness debat.
But will be lurking as i do

that debate is 100% not bro science, 48 hours is very beneficial. Im doing 5 days myself

 

[Azimuth]

Moreso, you can plan on having your sativa around longer after the drought to finish bulking...

We'll, I wonder if draughting causes enough stress to be a Hermie concern. That's why I suggested it would be an "end of times" activity.

If the thing Hermie's but you only have a few days left, no big deal. If you keep the normal schedule with a long running sativa and have many weeks to go after, that could be an issue.

Good work on this Krissi. Very interesting stuff

 

[Krissi Carbone]

A very interesting thread, @Krissi1982 . Such good references and research too. Not ready to begin droughting on my gals yet but I am going to soon. I have so many other things going on, I need to wait and make the-droughting-thing a priority after this harvest in 2-to-4-weeks.

I hope my results are as good as others here. Thank you (et.al.) for all your hard work and collaboration!

So happy to hear that Charlie. You will do well with this as you do with all other techniques you bring to the growing table and this forum! Thank you for the kind words, everyone involved, including all of you, are making this collaboration more beneficial!

that debate is 100% not bro science, 48 hours is very beneficial. Im doing 5 days myself

5 days! I've never heard of going that long! Hmmmm...something new for me!

We'll, I wonder if draughting causes enough stress to be a Hermie concern. That's why I suggested it would be an "end of times" activity.

If the thing Hermie's but you only have a few days left, no big deal. If you keep the normal schedule with a long running sativa and have many weeks to go after, that could be an issue.

Oh yea I mean we run the risk of a hermie, I can see why you would hold trepidations and want to do it towards the end of time so to speak. Just have to really be watching, not something you can leave for the weekend and just let em go yanno...

Good work on this Krissi. Very interesting stuff

Thanks so much Azi, I appreciate that very much and I know every viewer to this thread appreciates your active conversation, even if at some times you feel like you're talking to yourself lol

 

[iffey]

This sounds so interesting and where did you hear about that to begin with @iffey ?! We were discussing that last night but I had no idea what PPK was!!! Lol considering what you just told me, I think you have a good idea to implement this into your system. It's all trial and error man, we wouldn't have learned how to do anything until we tried it. You know as well as I do that those breeder specs are iffy, lol no pun intended. Don't be too concerned with the time, go by the LWA to determine when to stop it. Feel for your girl if you may.....I'm excited to see what you come up with. If you get it going, would you be interested at all in a future drought, documenting it for us as we will be with other mediums? That way we can enlighten 420 with your technique and your ability to drought while using it

I can not say where I learned about PPK.. that's a no-no here. But yes, a concept created by DELT9NSX around 2008.
It's a hybrid system that is both top fed via pulse pump and bottom fed via passive wick. I'm a simple guy and with his recipe I've been running 4 plants since 2008, on the same 20 lbls of NPK and 20 lbs of Calcium. No bonzai root hormoans or bud blast crap. NPK&Ca 600ppms. NOTHING ELSE> There is no requirement for PH checking drove me crazy in DWC, only use PH meter to be sure starting RO water (best with RO) is in range of 10ppms (+/- 10 ppms) PH is usually about 7.5. Heat is less of a grow room issue because O2 is drawn down thru the media/root ball when auto top irrigated. Setting up and balancing takes some getting used to but not very complicated.

Volume rez>control rez>pump rez>plant.. recycling on timers generally 1 QT / plant every 1-1.5 hours..

 

[Rexer]

NOTHING ELSE> There is no requirement for PH checking drove me crazy in DWC, only use PH meter to be sure starting RO water (best with RO) is in range of 10ppms (+/- 10 ppms) PH is usually about 7.5.

Gotta say, I'm hesitant to agree on the no PH in DWC. And 7.5 is way out of the ideal range for hydro.