400W - DWC - SCROG - Nirvana Hawaii Maui Waui

vietkush

New Member
INTRODUCTION:
This is my 2nd time doing a journal as well as my first time using the dwc (deep water culture) method. I am aiming for 1gpw.

Any advice and questions are welcome

BASE INFORMATION:

Strains:
1x Nirvana Hawaii Maui Waui (feminized)

Lights:
Un-cooled 400w HPS for veg and bloom

Pot size:
It is a home made "Two-Bucket DWC System" (google will show you what I mean) with 4x circular airstones with each stone getting 1800cc/min.
Reservoir's full capacity is 26L, but root space is only one 5 gal container.
I decided this for convenience when testing pH/ppm of the solution as well as refilling it.

Medium:
Tap water ~150ppm

Nutrients:
General Hydroponics Micro + General Hydroponics Bloom at ratio of 1:2

I just mix until desired ppm. I read my plant and when it becomes turgid and shows signs of yellowing, I know the concentration is too low and bump it up 100-200ppm. I pH the sol'n to 5.2, as the bucket with the airstone has a difference of +0.3 (e.g. rez pH is 5.2, root pH is 5.5), which I attribute to the dissolved oxygen.

A.K.A Lucas Formula (https://lucasformula.com/)

Feed Schedule:
I check pH almost daily, and adjust using phosphoric acid. I also check ppm weekly to see if it rises or decreases. I top up with solution of varying concentration. If ppm of rez rises, as plants are limp, I decrease ppm. If ppm of rez lowers, and plants are yellow and turgid, I increase ppm.

ppm is currently 1550, increased just a few hours ago.

Humidity:
30-60%

Temperature:
20-30C (68-86F)

Ventilation:
Both the fan blowing over tops as well as 6inch extraction fan running 24/7

Techniques:
SCROG:until end of grow
Super Cropping: a few branches in the centre, when they get too tall
Topping: only one time, to split the main stem into two.
Defoliation: I defoliate intuitively; too bushy and I strip off leaves until it is quite naked
Pruning: I take off a lot of new sprouts, as the plant has incomprehensibly many branches (see pics below)
 
Also, I let the root pH swing from 5.5 to 6.5.

The plant has been vegging for more than 4 weeks for sure, but not sure about how long exactly. I just veg until the screen is 80-90% filled, before flipping to 12/12.

Here are some pics

front:
20160520_214834.jpg


side:
20160520_214842.jpg


underskirt:
20160520_214902.jpg

There are a lot of branches; I pruned off all the leaves and many of the emerging tops under the trellis.
 
It has been 11 days since I updated the thread.

Changes:
-I defoliated the plant extremely heavily during that time. I tucked the plant today and the pics show before and after.
-Concentration of root space is 2050ppm at 0.5 conversion. pH swing is still allowed to go from 5.5 to 6.5.
-Instead of using General Hydroponics Micro and Bloom at a ratio of 1:2, I am now using General Hydroponics Maxibloom, which is a powdered fertilizer which achieves the same effect.

Pictures
Before-Front:
20160601_114401.jpg


After-Front:
20160601_132838.jpg


Before-Side:
20160601_114438.jpg

After-Side:
20160601_132845.jpg


I am not sure when flip to 12/12 will happen, but it will happen wheh there are tops touching all four sides of the trellis; the corners will be empty enough to accomodate any extra stretch. I will also defoliate when the tops are to the desired height to stop the stretch. This will allow me to use the effective penetration of the 400w HPS. The nugs will hopefully be around 9-10". Search "400w HPS penetration chart" on google images and you'll see what I mean.
 
It has been 9 days since I updated the thread.

Changes:
-tucked the plant once or twice
-concentration raised to 2500ppm. few days later, rose to 2700ppm, indicating that that concentration is too high.
-I am only topping up with pH'd water (150ppm) until the concentration stabilizes.
-No defoliation, as the plant did not need it, but may defoliate lightly soon.

Front:
20160610_220438.jpg


side:
20160610_220447.jpg


As you can see, the 4 edges are almost in contact with some tops, which means that it is almost time to flip to 12/12. I predict 1 or 2 more tucking sessions before flipping occurs.
 
Welcome my man :welcome: I know you are not too new to this as I have stumbled across your old journal a few days ago! Plant is looking really great, I hope you achieve the goals you set out for this one. Do you find it difficult to grow using DWC? I will be subbed for this one:Namaste: And also looks like I have first seat! :yummy:

I was re-reading the journal and realized that I forgot to answer your question!

I have grown in cheap potting soil, Promix HP, and DWC.
I would say that the difficulty is subjective. I do not want to turn the thread into soil vs DWC, but I'll try my best to compare the two as clearly as I can.

Soil/Promix:
-Frequency of maintenance is lower, but the time it takes is higher. (e.g. You only need to water every 4 days, but it takes around 1-2 hours to water the plants and to dispose of run-off +clean tools). In conjunction with other training methods (e.g. scrog,defoliation,etc.), you could be spending up to 4 hours, depending on how many plants you have.
-I'd say its more manual labour, as you have to water the plants, dispose the run-off, then clean the run-off dishes,etc. Potentially stressful for people with back pain.
-The responsiveness of the plants is also much slower, so any problems that arise may take awhile to show up and likewise, any adjustments will take awhile to take effect. Because of this, soil/promix is much more forgiving, especially for newer growers.
-Fixing over-nutrients is a pain, as you have to flush the medium (or water a few times with water) to get out the extra salt.
-pH of rootzone is hard to monitor, the only way to do it is when watering the plant, which is quite restrictive (measure pH going into the soil, and measure pH of run-off).

DWC:
-Frequency of maintenance is higher, but the time it takes is lower. (e.g. Must monitor and adjust pH almost daily; monitor and adjust ppm weekly. It takes around 15 minutes to adjust pH and then clean tools). Training methods still take around 1-2 hours per session of training.
-Much less manual labour, as you're basically only measuring pH/ppm and then adding acid/nutrients into the reservoir.
-The responsiveness of the plant is very fast, any adjustments can be observed in a day or two. Because of this, DWC is not forgiving at all, and damage occurs very quickly. If you are a beginner, I do not recommend it, UNLESS you are willing to pay close attention to the reservoir.
-Adjusting ppm is quite easy; either add nutrient water of higher ppm to increase ppm, or dilute with pH'd water. It can be done any time. Easy calculations: (Volume1*Concentration1)+(Volume2*Concentration2)=TotalVolume*FinalConcentration
-pH can be measured and adjusted any time.
-Temperature of water must be kept down. Adding bleach can resolve temperature issues, but it is not optimal.

All in all, the difficulty of DWC really depends on what you find difficult as well as the conditions you are in. Soil/Promix is more forgiving and there are fewer things to worry about, but it costs time and patience.
DWC is not as forgiving, and there are more variables to worry about (temperature, pH, concentration) but it gives the grower maximum control to push the plants to the limit.
Veg/flower time is also decreased significantly with DWC.

The other thing to note is the initial investment. DWC is more expensive, but due to higher yield/shorter time/re-usability, it is cheaper in the long run. Whereas with dirt, it is cheaper, but once it has been used once, it is not really recommended to re-use the soil.

Hope this clears up any misconceptions and feel free to ask more questions or even give suggestions!
 
No pictures for this post, but several changes from today:
-First rez change of the grow from 2500ppm and rising to a fresh batch of 1500ppm. Since I will flip it soon, I decided to change the rez to a lower concentration and use the following week or two to dial it in (Find the ppm where it does not fall/rise even when the plant is drinking water.)
-Tucked plant.
-Supercropped a few branches.
-Will do an extensive defoliation later or tomorrow, as the canopy is like a jungle.
 
Today is a big day!
Last tucking session before flowering; the canopy is slightly bowl-shaped. I will let the tops grow an inch or two before flipping to 12/12. It will most likely be in a few days and when I will re-top the rez.

feeding concentration has been lowered to 1300ppm.

Here are pictures to show how filled the screen is in addition to the underskirt and stem.
front
20160622_125236.jpg


side
20160622_125245.jpg


underskirt
20160622_124236.jpg


thick stem
20160622_124319.jpg
 
Beautiful Plants vietkush!! Have you grown this strain before and do have any idea about how much it will stretch during flower?
 
Beautiful Plants vietkush!! Have you grown this strain before and do have any idea about how much it will stretch during flower?

I have not grown this strain before, but the stretch I anticipate will not be too much. I know this, as clones were given to a friend; it is growing in DWC and is in the 3rd week of flowering, meaning that the stretch is done. From what I saw, I am timing it in hopes of having 10 inch long colas.
 
I'm new at the Scrog, but I'm wondering if you would recommend defoliating at this point? It's a sizable garden, really appealing.:thanks:

Since the screen is not 100% filled and because the stretch is no where near finished, I will NOT be defoliating at this moment.

What I will do is continue tucking and then let the tops elongate to hopefully 10 inches. When the tops are at the proper length or when the stretch is over (whichever happens first), I will defoliate.
 
Today is day 9 of flowering.
I have topped up with pH'd tap water twice now, trying to get around 900ppm. I notice that ppm keeps rising, indicating that the sol'n strength is too strong.
Tucked a few times. Slight bowl shape. The tallest nugs are around 6" or 7" above the trellis.
Pruned once. Waiting until about day 21 to do a moderate defoliation and to completely prune the plant of useless shoots.

Front
20160703_221232.jpg


side
20160703_221239.jpg


close up
20160703_221300.jpg
 
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