BT'z 2nd Grow: Super Lemon Haze & Golden Leaf

[BTzGrow]

Day 28- An update on my first LST efforts with this new grow. I've been doing some short term ponytailing, but now it's time to get serious. Drilled a few small holes and used some light pipe cleaners. Holding down the bottom three nodes branches that are growing out. Also pony tailed the tops and will see what the results are after 24hrs overnight. BTW, I have been doing 24/7 light schedule to this point with the T5, and so far not seeing any light stress at all. Will have to see what type of results come from the new LED. I'm really not expecting any real difference, as long as I start with enough distance. Just a note, check out the size of the trunk compared to the pipe cleaner. These SLH are hardy plants.

May 30th

• BTzGrow
• May 30, 2018

LST Action

May 30th

• BTzGrow
• May 30, 2018

LST action

 

[InTheShed]

I'm looking forward to growing one next year!

 

[BTzGrow]

@FelipeBlu and I both agree this is a very hardy plant. We will all enjoy the results I'm sure.

 

[BTzGrow]

Thursday afternoon as I was headed out I found a box on the doorstep. Early delivery from Amazon order of light. Yea! wasn't expecting until today later on.
Boxed inside another larger Amazon box. Bubble wrapped and secured in a dense foam pad on two sides.

HLG-100 Light

• BTzGrow
• Jun 1, 2018

Packed well with dense foam packing

4000K spectrum specifically for Vegging per HLG.

HLG-100 Light

• BTzGrow
• Jun 1, 2018

Driver and hangers in a separate box.

This is a lower wattage quantum board, so it doesn't require a heat sink. It does put off some extra heat that will have to be dealt with.

Light On

• BTzGrow
• Jun 1, 2018

Plenty of light as expected

Brought out my PAR meter and measured. With the light as high as currently set 29" above the floor of tent, the readings are well above the levels provided by the T5 2bulb fixture. 350PAR above the SLH tops on the outside, 300PAR above the center plants

Light On over plants

• BTzGrow
• Jun 1, 2018

PAR level over the outside plants at 350, 300 over center. Light at 29" off floor of tent.

I am going to double up the hangers so they are shorter and that will raise the light at least 3-4 more inches. Then will drop as needed with the regular ratchet rope hangers.

 

[DrDoob]

What do you think a good average par is? I’ve been doing a bit of research and have found conflicting info. I’m sure there is a certain amount of difference between strains, but I’ve seen a very nicely written study that said 1500 par and 86° is the perfect environment. I’ve also read that the plants can’t use more than 1000 par without adding co2 which the first study didn’t mention. I’m trying a little experiment by adding an extra light to get to about 900-1200 par in my 2’x2’. Things seem to be going well so far at week two of 12/12. But I won’t really know how big a difference there is for a couple more weeks.

 

[InTheShed]

Congrats on the light! Love those early Amazon deliveries. It's no good when they try to deliver after my office closes .

 

[BTzGrow]

What do you think a good average par is? I’ve been doing a bit of research and have found conflicting info. I’m sure there is a certain amount of difference between strains, but I’ve seen a very nicely written study that said 1500 par and 86° is the perfect environment. I’ve also read that the plants can’t use more than 1000 par without adding co2 which the first study didn’t mention. I’m trying a little experiment by adding an extra light to get to about 900-1200 par in my 2’x2’. Things seem to be going well so far at week two of 12/12. But I won’t really know how big a difference there is for a couple more weeks.

The Average PAR for most lights is distance dependent in my understand. Certainly from my tests that is so. The further away the lower the numbers and the closer the numbers get higher. So given the numbers that I listed between 300-350, @FelipeBlu also questioned. The assumption and typically correct is that directly under the light at a specific distance the PAR readings will be the highest. In this case the outside plants were actually higher so they were closer and higher PAR readings.

Now, on to a bit more of your question. I have read and studied a couple of articles. One from Hightimes Mag and another from a science institute on the subject of DLI (Daily Light Interval). The opinion is that Cannabis generally needs to have a DLI of about 25% during Veg and 35% during Flower. I ran the numbers in the equation(which I can share in a bit) and found that 600PAR for an 18hr lights on period generates the 25.9% DLI needed for Vegging. 900PAR for 12hrs lights on generates the 38.8% for Flowering.

I'm fairly sure the percentages can and will vary slightly dependent on the specific strain. I'm just not exactly sure how much difference that slight variation will make. I think pushing the 600PAR in veg up a little will not hurt, as well as pushing the 900PAR for flowering. They basically suggested that going over the DLI percentages did very little to improve plant growth or development. Interesting???

BTW, the research I was reading brought this aspect into play because they are saying that when a plant reaches it's DLI for the day, the lights can be cut back to nominal/minimal exposure just to maintain the light schedule. Basically suggesting a single CFL over a certain area. In large grow operations that would equate to very large savings in light and temperature control cost.

 

[BTzGrow]

A little disclaimer, I have no background in this field of expertise. Only dug up some info that looked interesting after reading someone mention DLI here and elsewhere and wanted to know more.

Here is the formula for calculating DLI with a quantum meter.​

μmol m-2s-1 x (,3600 x photoperiod) / 1,000,000 = DLI

- μmol m-2s-1 is a reading, or averaged readings, from the quantum meter

- 3,600 is the number of seconds in an hour

- Photoperiod is the period (in hours) of light exposure per 24 hours

- 1,000,000 is the number of μmols per mole

For example, 38.1 μmol m-2s-1 x 3600 seconds/hour x 12 hour photoperiod / 1000000 μmoles/mol = 1.6 mol. m-2d-1 (or 1.6 moles/day).

600PAR x 3,600 seconds x 18hrs / 1,000,000 = 38.8% It seems I published some incorrect numbers in the above post. We can all enjoy working this idea out, perhaps.


Now for the links to the articles:
Grow Hack: Understanding the Flowering Cycle for Higher Yields
Saturating DLIs for Flowering – Greenhouse Product News
https://www.extension.purdue.edu/extmedia/HO/HO-238-W.pdf

@FelipeBlu and I have discussed this to some degree and I feel we agree this has some really valid points. Most definately in the commercial grow arena particularly. I used this in my 1st grow to judge the distance to attain the basic DLI levels. No light stress. I guess one could increase the PAR readings by lowering the lights, and then turn off primary lights and keep a smaller light on. Seems like a lot of hassle in a small grow environment.

 

[InTheShed]

Have to keep in mind that the lower the light the smaller the footprint. Lowering it only works if you have close to wall to wall coverage with the fixture itself.

 

[BTzGrow]

Have to keep in mind that the lower the light the smaller the footprint. Lowering it only works if you have close to wall to wall coverage with the fixture itself.

Agreed, that is why I went with double lights side by side. As I lower them, I tilt them inward. The coverage stays really consistent. With a single light the lower the light gets to the growing area, the cone of light closes in also.

 

[DrDoob]

I get lost with math.

Just so I understand you are saying that with 600 par you reach the daily limit in about 18 hours, so using that forumla you could get about the same results from 1000 par for 11 hours? (Obviously needing to respect the plants photoperiod to avoid early flowering)

The study I read said the same thing about the plant reaching it’s daily potential. They even suggested that for outdoor grows in the intense summer sun that moving the plants into the shade after they’ve recieved enough light for the day can increase yields and health.

 

[BTzGrow]

I get lost with math.

Just so I understand you are saying that with 600 par you reach the daily limit in about 18 hours, so using that forumla you could get about the same results from 1000 par for 11 hours? (Obviously needing to respect the plants photoperiod to avoid early flowering)

The study I read said the same thing about the plant reaching it’s daily potential. They even suggested that for outdoor grows in the intense summer sun that moving the plants into the shade after they’ve received enough light for the day can increase yields and health.

Basically you are very correct in your read by my own understanding. Playing with the numbers again it appears I've had issues with the math also. It's looking like I may have dumb thumbed or had a senior moment in my math process.

Looks like in the moment 400PAR for 18hrs gives 25.9% 900PAR for 12 hrs gives 38.9%.

I agree with the idea that once the plant gets to it's DLI for a day, that backing off the intensity appears to be beneficial. How much I don't have a clue. I'm going to leave that up to the big boys with the big grows and the scientist.

 

[DrDoob]

It’s a very interesting topic for me because I have the solar power. It seems ideal to get the plants to their DLI under solar and just supplement when the sun goes down.

 

[BTzGrow]

Day 30 - Having received my new light yesterday and getting it adjusted in height, I felt time for topping the Lemon Sisters (SLH's) was over due. both showing 6th nodes and I wanted to top down to above the third node for Manifolding LST.

June 1st

• BTzGrow
• Jun 1, 2018

Topping of the SLH Lemon Sisters

I topped the 5th and developing 6th nodes together and trimmed the fan leaves a bit. Soaked in Clonex Cloning Gel and pushed down in to wet Root Riots. Spritzed the new clones with Clonex Clone Mist Spray. Will do that at least a couple of times a day as well as wipe condensation out of the dome I have on top of them. Temp in the tent is a little high. Looking to reduce perhaps with a blower fan exhaust.

June 1st

• BTzGrow
• Jun 1, 2018

Clones from topping.

I still had a 4th node remaining above the point I wanted to top down to above the 3rd so I cut again with the scalpel, soaked gel and placed a second possible clone. Trimmed off the large fans and we shall see what can or will happen. There are two branches coming out of the node that seem like they could be viable for a clone. Would it be interesting if I got a couple of plants that had two branches and had already been topped? Who knows?

Another couple of days and Gilda should be ready for the same treatment. She is so dense and tight that getting to the nodes to cut will be difficult. Perhaps letting her stretch a little more by raising the light isn't such a bad idea.

Temp in the tent is a little high. Looking to reduce perhaps with a blower fan exhaust.

Current plans for the clones that survive is to place in the 32oz Hempy Cups and grow on through flowering in a micro grow with lots of other 32oz Hempy cup clones. Perhaps as many as 12-15 little miniature plants growing straight up, and switched early to take advantage of the smaller tent. A few grams each, perhaps 1/4-1/3 oz each, maybe more for some?

 

[BTzGrow]

It’s a very interesting topic for me because I have the solar power. It seems ideal to get the plants to their DLI under solar and just supplement when the sun goes down.

Then, this process seems right up to perfect for you. Using a smaller light to keep in the light schedule would save cash for other nice things in the world.

The lights consume the same amount of energy regardless of the distance you set them at. So drop down to safe levels and cut them off and supplement. Awesome!

 

[DrDoob]

I’ve got clones of the two in the 2’x2’. Next round I will switch off two lights after 8 hours and keep the third on a full 12 and see how it compares.

 

[BTzGrow]

It appears I have developed a heat/temp issue in my tent with the new light. 86degrees is cutting things way to close especially after having just insulted the SLH Lemon Sisters. I have installed the T5 back inside and down low over plants as before and turned off the LED for the moment until I have received a new 4" blower and hose ordered just now and should be here by Sunday afternoon. Temp in other tent without lights on during the day is at 74 degrees which I'm assuming is close to the inside garage temp. Outside we are having a warmer than normal San Diego day. I'm also going to order an extension cord to go between the driver and the LED board so I can run the driver outside the tent. I don't think it generates that much heat, but mounted on the PCB that the LED's are already running really hot on can't be good for lifespan of the driver.

 

[InTheShed]

Derby has always said to run the drivers outside the tent! Good choice.

 

[BTzGrow]

I was able to get a 4" blower with 8' of dryer hose ordered for delivery on Sunday. Also ordered a 6' patch cable to go between the Driver and the light board, so it can be outside.

As I said earlier, I doubt the driver is creating any heat at the watts the board is pulling (100 dcwatts) and 99 acwatts at the wall. I do know the boards is very hot to the touch. Will pull exhaust out the top of the tent near the board and get it away from the tent some.

I have been running 24hrs and I'm really pleased with the outcome so far from the T5. Running 24hrs at ~200PAR gives about 69% DLI. For seedlings I feel that might be pretty good. The T5 just doesn't give the foot print of coverage as the plants get larger. Which is where they are going now.

 

[BTzGrow]

A moment of catch up, apparently I didn't press the Post Reply button for the above post on Friday. As it is I received all three items yesterday. One day delivery from Amazon. It's nice to live in a city that has a huge Amazon warehouse located close by.

Installed the blower and hose yesterday (Saturday) and it's helping lower the temp, but i'm still only using the T5. The patch cord extension cable for the light doesn't work. It's the correct size, but the connector on the board is slightly to big for the pin to fit inside the female cable. Going to do some cutting and splicing today. Fortunately I have soldering skills and equipment.