LED Grow Journal: Mars Hydro TSL-2000W vs Spider Farmer SF-2000

by Nebula Haze

This is the beginning of a cannabis grow journal featuring a grow-off between two LED lights:

Spider Farmer SF-2000

vs

Mars Hydro TSL 2000W

Why these LED grow lights?

  • We’ve received lots of questions about Mars Hydro and Spider Farmer (more than other “quantum board” or “spread style” LEDs)
  • They are each company’s design for a 2’x4′ grow space (my favorite tent size)
  • Summer is about to start in California and they both run cool

LED Light Stats

I am very skeptical of those estimated yields by the manufacturer but I would be happy with half that. I’ll update this section with more differences between the lights as I gain more experience with them.

Setup details

Dyna-Gro "Foliage-Pro" is a proven cannabis nutrient option for the vegetative stagePlusDyna-Gro "Bloom" is a proven cannabis nutrient option for the flowering stage

Experiment Procedure

Vegetative Stage

Flowering Stage

  • Initiate flowering stage with 12/12 schedule when the entire grow space is filled and plants average about 12″ (30cm) tall
  • Defoliate lightly week 1 and week 4 of flowering
  • Also lollipop plants on week 4
  • As plants grow, remove any leaves that are laying on each other making wet spots (to prevent mold)
  • Otherwise, leave plants alone until harvest so any differences come from the grow lights

Day 1 (April 1, 2021) – Clones rooted and ready for transplant

Rooted clones get moved to cups today!

Mama plants with cuttings in the aerocloner. Now that the babies have made roots, time to start the experiment!

 


 

Day 10 (April 10, 2021) – Clones ready to be put in pots

The clones for this test are rooted and happily growing in paper cups. They’re ready to get transplanted to pots and put into their respective grow tents this week.

Strains are Zweet Inzanity, Amnesia Lemon, and Pacific Punch. I’ll pick the 2 most similar clones from each strain for this test.

 


 

Day 17 (April 17, 2021) – Clones transplanted into tents with grow lights

I did my best to pick two identical clones for each strain to try to make this trial as fair as possible. Here are the clones immediately after being transplanted to 5-gallon pots and put into their respective tents. I tied some branches down to help spread them out (which is why some branches appear sideways). I anticipate these plants are going to explode with growth now that they’ve got big nice lights and plenty of room for their roots to grow.

Spider Farmer on top (white labels), Mars Hydro on bottom (with red labels to help remember that’s the “Mars” tent)

More about the Spider Farmer SF-2000 setup

Spider Farmer tent at 24″ away

Here are the Spider Farmer light levels at 100% power

Lux meter shows bout 33,000 lux at 24″ away in center

Here are the results with an Apogee meter (measured in µmol m-2 s). There is quite a bit of variance between the middle and sides of the tent (between 478-567 µmol m-2 s), especially compared to the Mars Hydro, which you’re about to see next

 

More about the Mars Hydro TSL 2000W setup

Mars Hydro tent at 24″ away

Here are the Mars Hydro light levels at 100% power

Lux meter shows bout 40,000 lux at 24″ away in center

Here are the results with an Apogee meter (measured in µmol m-2 s). I’m pretty impressed as this light seems to put very similar amounts of light (between 564-594 µmol m-2 s) throughout the entire tent onto every plant

Clones seem happy so far! Can’t wait to see how they grow this week now that they’re in their respective tents.

 


 

April 23, 2021 (Day 23) – Clones are growing and being trained to grow flat and wide

The plants took a little time to get adjusted to the new LED grow lights (they were yellowing a bit on top) but now seem ready to enjoy them at 100%. There wasn’t much growth the first few days after plants were put in the tents but they’ve been exploding in growth the last few days.

The Spider Farmer plants seemed to have adjusted quicker but the Mars Hydro ones may catch up this week. I think by next week there may be a clear leader for vegetative growth, but I also know from past grow light experiments that the light that does best in the vegetative stage is not always the one that produces the best yields in the flowering stage.

I did some plant training to make plants more flat and wide. As far as nutrients I’ve been giving them 1 tsp/gallon of Dyna-Gro Foliage pro at 6.1-6.2 pH.  The two Pacific Punch plants (left) seem pale/hungry (they’re also the biggest and fastest-growing) so I’ll be giving that plant slightly higher nutrient levels for a few waterings to see if I can get it to the same perfect green color of the others.

Spider Farmer tent before and after spreading out plants

Here is the Spider Farmer tent a little later after the leaves had time to mostly stand back up. Spider Farmer is currently 24″ away.

Mars Hydro tent before and after spreading out plants

And the full Mars Hydro tent. Mars Hydro is 26″ away (I moved it up a little because the tops were looking a little bleached) but I will let them grow up to it now that they’ve fully adjusted

Still neck and neck!

 


 

May 1, 2021 (Day 31) – Initiate the Flowering Stage with 12/12 light schedule

Strains typically about double in size after the switch to 12/12 so I’ve been watching the plant height. The plants have grown quite a bit and finally reached half the final desired size which means it’s time to start flowering them.

Today I initiated a 12/12 light schedule to get them to start making buds. Next week they’ll get their first defoliation.

The plants in the Spider Farmer tent seem to be growing at about the same rate as each other, but I noticed in the Mars Hydro tent that the right plant (Zweet Inzanity) is falling behind while the left plant (Pacific Punch) is almost double its size. All the plants are getting the exact same amount of water and nutrients, and the same light level according to the PAR meter, so it’s just how that particular plant is reacting to the Mars Hydro.

As we initiate 12/12 today, the overall average plant size in both tents still seems about the same.

The real exciting part is going to be how they produce in the flowering stage.

 


 

May 8, 2021 (Day 38, Flowering Day 7)

Although the plants don’t have any actual flowers yet, I’m seeing lots of pistils (white hairs) popping up everywhere and the plants have been stretching. They’ve grown about 6″ taller in the last week, and also just bigger and wider.

I gave them Vegetative nutrients for the last week because plants do a lot of vegetative growth the first few weeks after 12/12 and I wanted to make sure they had plenty of Nitrogen to power their growth. But starting today I am giving flowering nutrients (Dyna-Gro Bloom at 1 tsp/gallon). When I add that to my tap water it automatically sets the pH to 6.2, so no need for PH Down! A nice little bonus. So far I’ve been pleased with the results from Dyna-Gro.

Plants got a lot bigger this week, but still pretty well matched. By next week we should have little mini budlets to look at.

 

 


 

May 14, 2021 (Day 44, Flowering Day 13)

Plants are chugging along and seem to be fully into the flowering stage now.

Finally seeing buds this week. Or more like “budlets” right now.

I defoliated the plants today to thin out the leaves as some were laying on top of each other creating wet spots. I also removed leaves that were covering bud sites. Learn more about my defoliation method for these plants.

Spider Farmer tent before & after defoliation

Mars Hydro tent before & after defoliation

I filled a 5-gallon bucket full of leaves but the plants were so bushy it barely looks like I took anything. I plan to do a more robust defoliation and lollipop around week 4. The idea is to take away parts of the plant that will never amount to anything in order to force the plant to put all energy into fattening main buds as opposed wasting energy all over the plant. Until then I’ll only remove leaves that are covering bud sites or creating wet spots. That’s because bud sites tend to fatten more when they get access to direct light, and wet spots can attract mold and powdery mildew.

From the pictures above it may not look like I defoliated much, but I filled a 5-gallon bucket with leaves

 


 

May 21, 2021 (Day 52, Flowering Day 20)

Plants are still stretching but seem to be slowing down and starting to focus more on bud growth. Here’s an update of the tent and a comparison between the buds in the two tents.

Now let’s look at the buds starting with Pacific Punch (left plant)

Amnesia Lemon (middle plant)

Zweet Inzanity (right plant)

I’m surprised again that there doesn’t seem to be major differences between the buds in different tents. Next week they get their last defoliation and then it’s pretty much just waiting until harvest!

 


 

May 28, 2021 (Day 59, Flowering Day 28)

Wow the tents look TOTALLY different from last week!

You may remember at the beginning of the grow journal I wrote out a training regimen for the flowering stage. Since it is week 4, it was time for defoliation and simple lollipopping. After this point, plants are mostly going to be left alone until harvest. I won’t remove more growth or leaves unless I have to.

For defoliation, I removed all leaves that were…

  • laying on top of each making wet spots
  • on long stems (longer than 1″)
  • in the bottom and middle of the plant where light couldn’t reach
  • covering bud sites from the light

For lollipopping, I removed….

  • Any branches that were small and spindly
  • Any branches that were never going to make it to the top canopy (buds lower on the plant don’t usually fatten much, and can steal energy from top buds)
  • Any buds or growth that was right at the base of the plant where I know from experience it will never make decent buds

I took pictures so you could see exactly what that looked like.

Spider Farmer tent before defoliation

After defoliation and lollipop

Now onto the Mars Hydro tent.

Mars Hydro tent before defoliation

Mary Hydro tent with two left plants defoliated and lollipopped. The right plant still untouched. I thought this was a cool way to help see the difference between defoliated and undefoliated plants.

I noticed the beginnings of a calcium deficiency on the Pacific Punch plants close to the grow light where leaves are working hardest. It’s a pretty purple color thanks to the LED grow lights but it’s too early in the flowering stage to see discoloration on the leaves. When leaves turn color too early, they aren’t as good at photosynthesis and can therefore reduce your yields. Whenever you see a calcium deficiency, the number 1 first thing to check is the pH at the roots. Calcium deficiencies tend to show up when the pH is too low because it is poorly absorbed at low pH ranges. Other reasons to see calcium deficiencies are when using filtered water, low PPM (“soft”) water, or when you’re not adding any nutrients that contain calcium (cannabis plants LOVE calcium especially under LEDs).

Calcium deficiencies may appear purple especially under LED grow lights. In my experience, these deficiencies are most often caused by low PH at the roots. If that’s the cause, the solution is simple: give higher pH water.

My water has been going in at about 6.2 pH but when I checked the runoff water coming out of the Pacific Punch plants it was coming out at 5.2 pH. In coco you want a pH between 5.5-6.5 so this is way too low especially considering the water I put in had much higher pH. In response, all watering from now on will be given at 6.5 pH until the runoff water starts coming out closer to 6. Then I may lower it again to try to maintain between 5.5-6.5. I anticipate that the pH should be corrected within a few waterings and hopefully by next week. I’ll make sure to get a little extra runoff each time to help “clear” whatever is lowering the pH at the root zone.

 


 

June 5, 2021 (Day 65, Flowering Day 35)

Now we’re talking! Buds are forming and differences are starting to emerge. The Pacific Punch plants look like they’re only a few weeks away from harvest while the Zweet Inzanity plants are still all white hairs. It’s crazy to see the difference between strains.

Now onto my favorite part of doing side-by-sides… bud comparisons!

Pacific Punch (left plant)

Amnesia Lemon (middle plant)

Zweet Inzanity (right plant)

Since the leaves look good, I’ve been lowering the LEDs an inch every few days (currently about 20-22″ away). I plan to keep lowering it until plants show signs of stress or it gets to 18″ away. Bud fattening time.

 


 

June 12, 2021 (Day 72, Flowering Day 43)

Plants tend to stop needing as much nutrients when they get far enough into flowering that the plants aren’t growing many new leaves anymore. I noticed the tiniest bit of nutrient burn on a couple of leaves today so I decided it’s time to start backing off the nutrients as we enter into the second half of the flowering stage. I was using Dyna-Gro Bloom at 1 1/4 tsp per gallon, and I’m going to taper down to 1 tsp/gallon from here until we start getting closer to harvest.

The smells are pungent now. If I open the tent the smells pour into the room. The two Pacific Punch plants have a delightful sweet fruity smell. Normally I’m very reluctant to use the term “fruity” to describe the smell of buds because frankly most strains smell pretty stank. However, hats off to Square One Genetics because these buds truly smell delightful.

Not much else to say yet. The buds look a bit bigger but otherwise the appearance hasn’t changed significantly. I’d guess the plant on the right (the Pacific Punch) has 3 weeks to go, the middle (Amnesia Lemon) has 4 weeks, and the left (Zweet Inzanity) still has all-white pistils so it has at least a month to go. It’s packing on the weight though so I don’t mind but I’m surprised because it’s never run this long in the past. But that’s the luck of the draw with seeds. And who knows, it might surprise me.

 


 

June 19, 2021 (Day 79, Flowering Day 50)

Buds started falling over this week and I had to start tying them up using plant yo-yos.

Using plant yo-yos to hold up falling branches. Here’s how I attached it to the top of the tent

The yo-yo-attached to a branch (these are made specifically to hold onto cannabis branches without bothering the buds)

The plant on the left appears to be held up by strings. Those are the yo-yos!

Not much else to report on except that the smell is starting to get a little crazy. When I open the tent I feel like my face gets smacked by the scent lol

 


 

June 24, 2021 (Day 84, Flowering Day 56)

Whew, this week should have been called “yo-yo week” consider how all the buds started falling over, especially in the Mars Hydro tent 🙂

The Mars Hydro buds look like they might be getting bigger (except the middle plants seems bigger in the Spider Farmer tent) but the Spider Farmer buds seem like they smell more when I open the tent… I can’t wait until harvest the suspense is killing me!

 


 

July 2, 2021 (Day 92, Flowering Day 62)

I got requests to see the plants in their tents with the LEDs on to get a sort of better look of the inside of the tents. Here they are!

Spider Farmer tent (flowering day 62)

Mars Hydro tent (flowering day 62)

So sparkly!

We are getting sooooo close to harvest. I strongly anticipate that next week’s pictures will include the buds drying! I will give all the plants one last “photo shoot” before harvest so you get an up-close-and-personal look!

 


 

July 9, 2021 (Day 100, Flowering Day 70) – HARVEST DAY!

Ah, harvest day. So satisfying and exciting.

Here are a few more pictures of the Spider Farmer tent in different lights

Here’s what the plants look like with a flash (which helps you see how big the buds are all the way down)

Pacific Punch under Spider Farmer LED (left plant)

Amnesia Lemon under Spider Farmer LED (middle plant)

Zweet Inzanity under Spider Farmer (right plant)

Here are a few pictures of the Mars Hydro plants in different lights. If you click on them you may be able to see all the strings from plant yo-yos I used to hold the buds up

Here’s what the Mars Hydro plants look like with a flash

Pacific Punch under Mars Hydro LED (left plant)

The Pacific Punch buds were super sparkly and purple in both tents. Genetics makes a huge difference in bud results!

Amnesia Lemon under Mars Hydro LED (middle plant).

Zweet Inzanity from the Mars Hydro tent. This strain always comes out sparkly and yields well

It’s hard to get a clear picture because the trichomes reflect light back

Buds drying!

This is exciting! I have an AC and a dehumidifier to keep the room at 60°F and 60% humidity while they’re drying. I hung buds from inside the tent with the exhaust fan turned to the lowest setting for gentle airflow. I’ve found this environment provides consistently great results even if you’re drying a lot of buds at once.

I’m actually a little amazed at just how similar the two tents and all the buds look. I’ve done side-by-side grows before with clones, and usually, there are at least some visible differences. I can’t wait to see what the scale and lab results have to say. One thing for sure is both these lights performed awesomely!

 


 

Stay tuned for the next update!

~Nebula

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