How to achieve uniform THC and CBD results with the use of UVA UVB lighting.

Here is a quick update about how to achieve a uniform consistency when using UVA UVB lighting to grow medical marijuana.

Based on my last two years of testing I have found that using UVA UVB lighting will increase THC % by 3-5% on average.

Additionally we found where the light is placed makes a big difference as well as where the sample taken for testing or consumption also makes a noticeable difference. 

The lighting must be over top of plants and only the part of the plant receiving direct lighting from the UVA UVB bulbs increases. Which means the bigger the plant the more UVB UVA lighting you will need. Nowhere else on the plant does it show any increases in potency other than where the light is directly applied.

Also the location of the cutting taken for testing or consumption varies 3-5% as well. With this information it is possible that the top 6 inches of the plant could be 6-10% higher in THC than the lower branches.

Using the UVA UVB lighting in vedge or seed stage makes no difference on potency only some minor leaf curl is noticed if used in bloom only. All new leaves will adjust and not show any curling.

SCROG For Best UVA UVB Light Coverage And Uniformity

Based on this knowledge it would be best to grow medical marijuana plants in a technique called SCROG or screen of green. 

Basically you are growing a plant out wide not tall. A plant could be five feet wide but only 12- 18 inches tall. What this does is allow all the light to be used by the plant evenly and uniformly. This will eliminate the huge variance in THC and CBD potency. It will also eliminate all those small airy, fluffy flowers that are no good to consume other than maybe edibles. Resulting in large easy to trim flowers that all have the same flavor, taste, smell, hardness, density, potency and bag appeal.

 It also allows you to increase your yield by at least double if not more while growing fewer plants. This is a benefit if you live in a state where the legal limit of plant count is very low. To achieve this plants will need to be vedged longer and allowed to get fuller and taller. Top and crop as much as possible to make the plant short and wide.

Here is an example of a five foot SCROG set up in a 20 gal pot grown in a soil or soilless media. The pot size can be dropped to a 10 gallon or 15 gallon size with similar results.

It is my hope that all my research and testing will benefit everyone as well as advance the growth and knowledge of the industry resulting in better medicine and less chronic pain patients loaded up on highly addictive pain killers.

Links to related blogs:

How to Grow Medical Cannabis Like A Pro

UVB UVA Study Results Increses Marijuana Cannabis Potency By 3-5%

Updated UVA UVB Medical Marijuana Study Results

Updated UVA UVB Medical Marijuana Study Results

I am pleased to say I have done another round of UVA UVB testing and it has been completed.

The objective was to determine if the location of the UVA UVB lighting effects the entire plant or just the area in which the lighting was placed.

I had the lighting placed on one side of the plant for the entire bloom cycle. Normally I would have them overhead. Then after the cycle was over I took samples from both sides of the plant. I sent in both samples that I had taken for testing.

The test results showed that only the side facing the lighting increased 5% from 23% to 28%!

This is a very important finding. Not only is the fruit closest to our grow lighting 3-5% stronger with the addition of UVA UVB lighting it will also increase the potency another 3-5% only where the UVA UVB lighting is placed.

With this testing completed it will be important to locate lighting all around the plant as much as possible or directly overhead. I previously used the Reptisun 10.0 UVA UVB 4ft T8 bulbs. I am now using the Reptisun 10.0 UVA UVB T5 4ft bulbs. They are 2x stronger and will penetrate deeper into the canopy.

Next round of testing will be to see if waiting till last 2 weeks of bloom to turn on the UVA UVB lighting will still result in the dame 3_5% increase.

Link to Reptisun 10.0 UVA UVB T5 HO 4FT bulbs UVA

How To Grow Medical Marijuana Like A pro

UVB UVA Lighting Study Results Increases Medical Marijuana Potency 3-5%

UVA UVB Lizard light testing results.  Date Feb 2013- Dutchman Enterprises

I just completed 2 full years of testing on over 10 different strains and have reached the conclusion that the UVA UVB light spectrum will add 3-5% THC and .0-.5% bcd over all strains tested.

I have done 6 complete grows from veg through bloom each one tested with the lighting and without the lighting alternating each crop. One on and one off. Each time the crop with the lights on would jump 3-5% with the lights off it would decrease 3-5%. I have assumed an error margin of 2%

My test results seem to be right in line with what other people have experienced over the years. I could not find any recent data online so I Decided to do my own research and testing.

Some strains tested are as follows when under Lizard Lights.

Chem dawg 27%

OG-18 25%

Holy grail Kush 28%

Critical + 23%

Tohoe OG 24%

Grape Ape 23%

White Fire OG 25%

Dead Head Og  24%

Chem Valley kush- shit pheno 15%

The difference in potency is so obvious that all my patients would complain about the lack of potency on the crops that I did not use the UVA UVB lighting!

UVA UVB Light Exposure

I have found it is best to expose them to it from time they are rooted. This will give them time to acclimate to the lighting. It does not make any difference to the potency if you use the lights in bloom only. The only difference is if you do it in bloom only you will get leaf curl but it does not seem to stress the plant or hurt it in any way. I would start them off slowly and build up to the full 12hrs in bloom if you are not going to veg them under the UVA UVB lighting.

I started off my strains in low doses on a timer in 2 hr increments on and off and slowly each day increased them as I was scared to kill them initially due to some research I had done on this topic in online forums. 

I soon found that it did not matter at all. You can hit them with the lighting 24hrs in veg and 12 hrs in bloom with no adverse effects except a little leaf curl at the ends if they had not been previously acclimated to it at the beginning of life stages (rooted). This is why I would recommend exposure as soon as possible.

I purchased the new 4 ft Zoo MedReptiSun 10.0 UVB/UVA Bulbs 

These bulbs were chosen because they reach the deepest and furthest away.

With these 10.0 bulbs penetration is 18-24 inches from the light. 

The older 8.0 or 9.0 bulbs were 12 inches or less which did not give much room for plant location in my 8x15 room.

UVA UVB Light Test Results

I had every batch of plants tested by Cannalytics for accuracy. I have also found that where you take your sample on the plant also plays a role in test results. The THC % plants can vary anywhere from 3-6% difference based on where sample was taken top, side or bottom of plant. 

I am no scientist so I can't say 100% that it does not alter the plants genetics but based on my knowledge of genetics and my own research I do not believe the genetics have been altered at all. What has happened is just a natural stress response by the plant to protect itself from the ultraviolet rays. 

To prove this even more is the fact that each strain dropped back 3-5% when it was not under the UVA/UVB lights. Even when I had them under the UVA/UVB lights in veg but not under the lights in bloom they did not increase in potency enough that I could measure a change.

Further UVA UVB Questions To Answer

Some further questions I would like to get an answer to is if the light is positioned on one side of the plant instead directly over top of the plant does the whole plant respond to the uva uvb stress the same throughout or does it only increase potency on the side the light is on? I will need to take two samples off one plant and have them analyzed.

I was able to get the double 4ft fluorescent light fixtures for $50 each that had a 15ft electrical chord plug attached. I found the ReptiSun 10.0 4ft bulbs for $18.95 each plus a few bucks shipping. I will find who it was and post it when I do. My total cost for 6 fixtures and 6 bulbs was around $400. 

I have used them for 2 years on and off so pay off has been good. In my opinion it is well worth it to run the UVB UVA bulbs. It will set your product apart from every one elses in your area. Think about it to be a beginning grower and have strains testing out at 27-28% and seeds were gathered from online seed banks is pretty darn good!

UVA UVB Lighting To Kill Powdery Mildew

YouTube Channel How To Grow Marijuana Like A Pro

I hope this helps someone, happy growing

Dutchman Enterprises

UVA UVB MEDICAL MARIJUANA LIGHTING LIZARD LIGHTS THC POTENCY INCREASE