12/12 From Seed Experiment - 21 Strains

Hot Diggity Sog

Well-Known Member
The girls are looking fantastic now! Topped off with 4 gallons @25% strength...no PH down. PH had crept down to 5.2 overnight and the topoff has it at 5.8 now. I turned the 2nd feed pump on for a couple of minutes but unfortunately the problematic tube started to overflow. No worries though...I'll be shimming that side soon and will start experimenting with different pump sizes to find the sweet spot.
 

akhiymjames

Well-Known Member
Yea it seems like you found the problem with the water flow not flowing as good as it should and having stagnant water. Your system is good and I'm sure those roots are clogging things up a lil too but that just shows how good you've got them going. Glad to hear they are looking back good cant wait to see what this produces. If you can get this mastered I don't think you will need to prototype or experiment with new system cus this looks amazing.
 

Hot Diggity Sog

Well-Known Member
Yea it seems like you found the problem with the water flow not flowing as good as it should and having stagnant water. Your system is good and I'm sure those roots are clogging things up a lil too but that just shows how good you've got them going. Glad to hear they are looking back good cant wait to see what this produces. If you can get this mastered I don't think you will need to prototype or experiment with new system cus this looks amazing.
Thanks man! Yup, I'm going to devote all of my mental energy into this. Construction on the next one starts soon. I'll be germinating seeds and establishing roots DWC style right in this same octagon approx 20 days before these finish. This is part of my perpetual plan as well. Think of a childrens swimming pool with foam board on top with 2" holes to hold 100 ish net pots. Put them inside the octagon 20 days before harvest. Once the flowering girls finish, these will have roots long enough to go right into the tubes for the next round. 1 light still and shave 20 days off the total time. Almost 4 1/2 harvests per year per octagon.

Regarding clogging, I'm not really seeing any signs of this. Are the roots causing the water level to rise a little? Yes, I think they are.
 

Hot Diggity Sog

Well-Known Member
@Sativied
I'm not looking to challenge your experitse but it would seem to me that if I aim for shallow water depth that might be the best. The less water in the tubes the better the flow will be. With my 8 sided design, I could actually design this so the tubes ran with a slight down hill bias. Providing the plants go in with mature enough roots, I'm not really seeing any downsides. Thoughts?
 

Sativied

Well-Known Member
Keep in mind you are using round tubes so a shallow flow automatically means a narrow flow (unlike for example @skunkd0c's trays which are flat and wider allowing him to spread out the roots and the flow. I'd love to see a pic Skunkd0c, of a tray alone, never entirely understood how your system connects).

tubes.jpg

Put it in the pic already, but running shallow in a tube fits better with running sprayers in between netpots.

My tubes are slightly tilted too, but then without the dam the flow would be very shallow and narrow, i.e. the tubes would drain faster than the pump could supply enough new water. Only a dam changes that effectively. A bigger pump raises it only slightly, it just makes the same stream go faster (up to a point of course, but then the flow becomes to harsh).

By itself either way should work. In addition to a shallow flow you could even put that flow on a timer. Many different ways to Rome. But, I don't agree with this conclusion per se:
"The less water in the tubes the better the flow will be."
It's true that tubes that hold more water need a bigger pump to recirculate everything often enough but the amount of water in the tubes is by itself not a determining factor of the quality of the flow. It depends on what causes the increased amount of water in the tubes. The amount you recirculate is what matters. If you recirculate 100 gallon per hour with 10 gallon in the tubes that flow is better than recirculating 50 gallon per hour with 7 gallon in the tubes for (an exegarrated) example. A shallow flow will also have a harder time overcoming obstacles, like concentration of roots, i.e. you risk more pooling. Also, just perception and not science to back it up but my root mass gets as high as my flow.

I'm going to look up a formula I once posted in a bit. By itself not very practical for us but it shows what's important.

Also, if you start in DWC I would flood them to make sure those DWC submerged roots are submerged in the tubes as well, or at least add a means to start flooded and lower gradually to avoid transplant stress/delay (first problem I ran into pre-dam).
@Sativied
I'm not looking to challenge your experitse
I enjoy sharing my thoughts extensively because I know you won't simply replicate it without giving it thought yourself. In the end you got to do what you think is best for your setup :)

Great to hear the plants are doing well again. Try to avoid ph lower than 5.6 if you can (should be less of an issue with the AB. If it still drops too fast start out a little higher, like 6.3. Note the small notes in the ph graph I posted, there are a couple of other factors that play a role. Too low and too high ph has chemical reactions that essentially reduce nutrient availability too.
 
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Sativied

Well-Known Member
Found it: Ideally, with 4kg of roots per square meter you need to refresh the root zone with 100 liter water per hour, which should contain 8 mg oxygen per liter.

That's from a large professional test setup and holds true for most (if not all) plant species.

Fresh water at 68f contains (according to some aquarium site) avg. of 9.1mg oxygen per liter. In sea water this is nearly 25% less, 7ish. "Any dissolved solids will reduce the dissolved oxygen level by that amount, not just salt." It's more or less the same for fish. Using air stones, but also things like return waterfalls and the flow itself should be enough to get to that 8mg. Plenty of folks figured out that it's not hard to reach that max DO level, it's maintaining it that's the challenge. 8 mg in the rootzone is not enough if it's not refreshed often enough. Once that is reached however, there's imo no benefit to having parts of roots not submerged, on the contrary. The flow flowing through all roots is what makes the system so great.
 

Hot Diggity Sog

Well-Known Member
Found it: Ideally, with 4kg of roots per square meter you need to refresh the root zone with 100 liter water per hour, which should contain 8 mg oxygen per liter.

That's from a large professional test setup and holds true for most (if not all) plant species.

Fresh water at 68f contains (according to some aquarium site) avg. of 9.1mg oxygen per liter. In sea water this is nearly 25% less, 7ish. "Any dissolved solids will reduce the dissolved oxygen level by that amount, not just salt." It's more or less the same for fish. Using air stones, but also things like return waterfalls and the flow itself should be enough to get to that 8mg. Plenty of folks figured out that it's not hard to reach that max DO level, it's maintaining it that's the challenge. 8 mg in the rootzone is not enough if it's not refreshed often enough. Once that is reached however, there's imo no benefit to having parts of roots not submerged, on the contrary. The flow flowing through all roots is what makes the system so great.
OK. Thanks for the input as usual. I will adjust my PH to get it more in line. If I'm going to have these 1/2 point overnight drops then my range should be 6.2 to 5.7 or thereabouts.
I'm also going to take some pictures to try and illustrate the tube transitions in the new design.
 

Hot Diggity Sog

Well-Known Member
@Sativied
Another quick question: You had mentioned a while back about running EC 1.0 from start to finish. I'm currently working on the DWC design for seedlings before they would enter the tubes. Using 2 inch net pots and 1 1/2" rockwool, they will need top watering daily most likely. If I top water with PH'd only water but their roots were to dip into 1.0 EC at a very early age, such as a week old, do you think this is OK or is that too hot for them? The main reason I ask is that it would be a lot easier if the seedlings could receive water from the same rez as the flowering plants that are nearing completion.
 

Sativied

Well-Known Member
I usually run 0.72-0.86 EC in my pre-veg (first 10-14 days from seed) dwc boxes. Then when I move to tubes they get roughly 0.9-1.1. I need to keep it low in the dwcboxes because it rises too fast ( and ph drops) if I run higher, the boxes are small so fluctuations happen fast. I don't think they will actually burn at 1.0 ec, especially combined with the topwatering, but it might be a little stressfull on the roots. I think if everything else is optimal it could work.

Also, that's after 1 week of that first 20 days of the next plants for the octagon, and thus the last 13 days of the flowering plants right? The plants slowly reduce nutrient uptake late in the cycle, so I run slighlty lower then already, pretty much down to that first range I mentioned above. The easy solution would be running 0.8 EC the last couple of weeks, which is plenty at that time.. The last week or two I just add water instead of topping of with nutes, to lower the ec along with the decreasing demand. So that's potentially an issue.

Another thing to consider is that the plants will get in a worse shape near the end, some perhaps more than others, possibly need to harvest in stages with old roots going bad. In that case you obviously don't want to use that same water for the seedlings and use a fresh solution instead.
 

Hot Diggity Sog

Well-Known Member
I usually run 0.72-0.86 EC in my pre-veg (first 10-14 days from seed) dwc boxes. Then when I move to tubes they get roughly 0.9-1.1. I need to keep it low in the dwcboxes because it rises too fast ( and ph drops) if I run higher, the boxes are small so fluctuations happen fast. I don't think they will actually burn at 1.0 ec, especially combined with the topwatering, but it might be a little stressfull on the roots. I think if everything else is optimal it could work.

Also, that's after 1 week of that first 20 days of the next plants for the octagon, and thus the last 13 days of the flowering plants right? The plants slowly reduce nutrient uptake late in the cycle, so I run slighlty lower then already, pretty much down to that first range I mentioned above. The easy solution would be running 0.8 EC the last couple of weeks, which is plenty at that time.. The last week or two I just add water instead of topping of with nutes, to lower the ec along with the decreasing demand. So that's potentially an issue.

Another thing to consider is that the plants will get in a worse shape near the end, some perhaps more than others, possibly need to harvest in stages with old roots going bad. In that case you obviously don't want to use that same water for the seedlings and use a fresh solution instead.
The lower EC towards the end makes sense but I had not considered the older roots going bad. OK.
 

Alaric

Well-Known Member
I usually run 0.72-0.86 EC in my pre-veg (first 10-14 days from seed) dwc boxes. Then when I move to tubes they get roughly 0.9-1.1. I need to keep it low in the dwcboxes because it rises too fast ( and ph drops) if I run higher, the boxes are small so fluctuations happen fast. I don't think they will actually burn at 1.0 ec, especially combined with the topwatering, but it might be a little stressfull on the roots. I think if everything else is optimal it could work.

Also, that's after 1 week of that first 20 days of the next plants for the octagon, and thus the last 13 days of the flowering plants right? The plants slowly reduce nutrient uptake late in the cycle, so I run slighlty lower then already, pretty much down to that first range I mentioned above. The easy solution would be running 0.8 EC the last couple of weeks, which is plenty at that time.. The last week or two I just add water instead of topping of with nutes, to lower the ec along with the decreasing demand. So that's potentially an issue.

Another thing to consider is that the plants will get in a worse shape near the end, some perhaps more than others, possibly need to harvest in stages with old roots going bad. In that case you obviously don't want to use that same water for the seedlings and use a fresh solution instead.
Interesting points:

Any idea how much yield reduction you would expect if running staggered veg and flowering and one size fits all nute soup (all 2' - 5' plants veg and flower)?

A~~~
 

Budget Buds

Well-Known Member
Holy shit man :) I just read all 74 pages of your growing journal , It took me almost 5 hours to read it all . Its nice to see what others have come up with and the problems they have to overcome. I'm really diggin the new setup and all the automation you have installed to make things easier for yourself. Keep up the good work and the best of luck !!
BB
 

Alaric

Well-Known Member
Did a little digging on the GH aeroflow "laser drilled" spray line------I don't see anything aero about it.

http://generalhydroponics.com/site/gh/docs/instructions/LaserSprayline_inst.pdf

I molded one of my first designs after it but used 6" pvc tubes and 1/2" pvc with 1/8" holes (never clogged up).

@Satived I did this with you in mind buddy----perhaps I dreamed it:) But I vaguely remember you saying something about sprayers used in the Aeroflow----could be wrong (again).

A~~~
 

Sativied

Well-Known Member
Interesting points:

Any idea how much yield reduction you would expect if running staggered veg and flowering and one size fits all nute soup (all 2' - 5' plants veg and flower)?
Zero grams.

I already use the same soup for tubes (flower) as DWC (veg). I.e. After mixing a fresh batch in the large rez I use some of it for dwc (or hempy or coco but then I do ). They are however not connected to the same rez so I can mix a soluion for it separately, and top off separately.

Zero because running lower ppm does not equal underfeeding, just means you have to top off with nutes more often to keep it from really dropping too low and prevent imbalance. The whole concept of flower nutes is largely bs but one could simply run a little more A than B in veg and a little more B than A at the end (A is high on Ca and N, B high on P).

It's actually quite normal in large hydroponic greenhouses where plants of various age and size are in the same tray or bath.

A larger plant transpires more, has more root mass, so already takes up more nutrients. I.e. A larger plant does not necessarily require a high nutrient concentration, but will use more nutes regardless so will reduce the nutrient level in the rez faster.

So the larger flowering plants take up nutrients faster than the seedlings in veg, which means the EC will drop faster and you have to add nutes more often.

There's from the plant's perspective really no reason to stay on that socalled sweetspot where water uptake and nutrient uptake is balanced. Convenient for the grower, but all the plant needs is being able to take up enough nutrients over time. It can do that at 600ppm but also at 400ppm. The difference is that the 400ppm makes the rez ppm drop faster so requires more maintenance.

I think the common misconception about the sweetspot is caused by an assumption that drinking from a high ec soup equals more nutrient uptake. Which is not necessarily the case. True for Ca and perhaps a few others, and in soil drinking pulls nutrients to the roots (flow beats that) but nutrient uptake (cation anion exchange) is a separate process. The EC climbing or dropping does not directly say something about the amount the plant needs to reach its genetic potential.

Above all, unlike bloom boosters etc suggest, those few grams of nutrients are just a small factor. And then it's still the total amount of nutrients it takes up over time that's key, not the concentration of the soup it takes it from. Lower ppm is less stressful on the roots and plant which in turn maximizes allows for a more consistent nutrient uptake.

That run I did to see what the minimum would be was at 360ppm, half being tap, and I don't think it reduced the yield by a single gram (impossible to measure so exact because there are so many other variables). It would perhaps become obvious on a hectare sized grow, but if it's like 2-5% it's hard to notice in a single bulb grow. That's also exactly the ppm I start out with for seedlings (that rooted through the cubes).
 

Sativied

Well-Known Member
@Satived I did this with you in mind buddy----perhaps I dreamed it:) But I vaguely remember you saying something about sprayers used in the Aeroflow----could be wrong (again).
The spray line in the aeroflo does not actually have separate sprayers but just holes. It still comes down to the same thing. It has indeed nothing to do with true aero, adding a few sprayers to it wouldn't change that either, it's to spread out the solution instead of having an entry point on one side, and not actually to mimic aeroponics. The spray line in the aeroflo is pointless, unless you run very long trays/tubes the solution can be pumped in on one side without adverse affects (depleted nutrients or oxygen at the end of the line).
 

Alaric

Well-Known Member
Zero grams.

The whole concept of flower nutes is largely bs but one could simply run a little more A than B in veg and a little more B than A at the end (A is high on Ca and N, B high on P).

It's actually quite normal in large hydroponic greenhouses where plants of various age and size are in the same tray or bath.
Thanks---good read. Conclusions I've reached also. I do run my aero cloner / freshly rooted babies with separate rez ( large kitchen trash can, more N added).

I take my cuttings from veg plants 60 days old from cut till 12/12 using the same bloom soup.

It seems to me--- cuttings taken from veg plants feeding on a low N diet roots a little faster / better.

A~~~

I tried sending you a PM----wouldn't let me----still selecting pics of this journal (almost two decades)
 

Hot Diggity Sog

Well-Known Member
Chapter 3 Update
Day 46
Flowering Day 13

Girls are doing pretty good. Still having some curling and spotting issues but collectively they look pretty healthy. Added some PH Up last night...1st time I've ever used PH Up. To my surprise, the PH remained stable overnight. Sitting at 6.0 currently. EC very steady at 1.1.

The pictures did not come out very well so I'm only going to post a few.

DSC_0003_00003.jpg DSC_0004_00004.jpg


And a few close-ups of some buds starting :)

DSC_0009_00009.jpg
DSC_0011_00011.jpg
 

Alaric

Well-Known Member
The spray line in the aeroflo does not actually have separate sprayers but just holes. It still comes down to the same thing. It has indeed nothing to do with true aero, adding a few sprayers to it wouldn't change that either, it's to spread out the solution instead of having an entry point on one side, and not actually to mimic aeroponics. The spray line in the aeroflo is pointless, unless you run very long trays/tubes the solution can be pumped in on one side without adverse affects (depleted nutrients or oxygen at the end of the line).
My Knock off before panels added-----drain port raised in tube to set nute level.
flexhose.jpg

Edit: Just noticed an important change I made----the blue cobra line was positioned before the drain port----helps prevent roots from making it to the drain

A~~~
 

Alaric

Well-Known Member
Chapter 3 Update
Day 46
Flowering Day 13


Girls are doing pretty good. Still having some curling and spotting issues but collectively they look pretty healthy. Added some PH Up last night...1st time I've ever used PH Up. To my surprise, the PH remained stable overnight. Sitting at 6.0 currently. EC very steady at 1.1.

The pictures did not come out very well so I'm only going to post a few.

View attachment 3467430 View attachment 3467431


And a few close-ups of some buds starting :)

View attachment 3467432
View attachment 3467433
Already a jungle in there (yikes with 53 Days left).

Suggestion:

Train (trellis) your plants so they're growing out toward the light pruning a few of the lower branches thats going to be shaded anyway.

I always assumed plants would naturally grow toward the light----NOT SO----always up---must be this gravity thing.

I admire your commitment----hope you don't run out of gas.

A~~~
 
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