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Critical Mass Grow Journal

critical mass grow journal
Posted by: Samuel Thomasino Category: Grow Journals Comments: 0

Critical Mass Grow Journal

Critical Mass Strain + Grow Setup Info

Within this Critical Mass grow journal you will see clear evidence of why it is the highest yielding cannabis strain available on the market. This version of Critical Mass is by Dark Wizard Genetics and proves itself to be a stable and dependable strain.

critical mass strain

For more details, or to purchase these seeds, check out the official strain info on the Critical Mass seeds page

In this grow journal the plant will be grown under these conditions:
Lighting: LED bars with 25 x 13w bulbs
Light Cycle: 18/6 & 12/12
Temperature: 21-26°C
Grow Space: Indoor
Medium: Homemade Compost with dry plant food(seaweed meal, chicken manure, etc.)
PH level: 6.2-6.4

led bulb
Here are the statistics for my LED bulbs when located 50cm above the canopy.


Starting them off in Rockwall cubes, temperature between 24-25c.

grow space
Here’s the veg room, 60cm(L), 32cm(w) 70cm(H), 3 x 13w led bulbs and a USB fan.

Starting with 4 x 2.5ltr pots inside the propagator. I will flower these Critical Mass plants when they are around 10-12″ high, they normally finish around 24″-36″ at about 3-4 weeks in flower.

I will be repotting the 4 plants into 29 liter pots after 5 days in Rockwool. They will spend a total of 4 weeks in veg if everything goes well I will turn them over to flower after this.

critical mass seedlings
Seedlings have all come up now.

I have rehomed them into 2.5 litre pots and in around a week they will go to their final pots which are 29 liters in size.

Seedlings – 5 days old

critical mass 5 days
New picture to see how much they have grown in the last 3 days. The total age is now 5 days from sprout.


Critical Mass at Day 12

veg day 12
They have doubled in size in the last few days. They are officially moving into the veg stage, so I will call this day one in veg.
Humidity has stayed between 43% and 50%, temps between 22-28c over the last few days. Everything going slow and steady just the way I like it.

Critical Mass at Day 14

Looking at the plants this morning, I thought they could be potted up in a week’s time, so I spent over 2 hours mixing the compost, sand, and dry plant food.
mixing compost
mixing compost
plant food mixed up in the sharp sand before mixing it into the compost

Chicken manure (50g) 4.5 3.5 2.5, mg 1.0 cal 9.0
Bone meal (25g) 4.5 16.3 0
Westland Superphosphate (25g) 0 17.5 0
Sulphate of Potash (25g) 0 0 48

3 strong critical mass plants

Critical Mass at Day 17

Humidity in the grow space is just over 50%, would be nice to get it near 60% (the leaves slightly curled when the humidity dropped to 40%)
critical mass day 17

Critical Mass on Day 19

day 19
I changed the layout of the pots this morning and put everything in place to get a feel of the setup and the size of the pots/plants in the room. Each pot has about 25 liters of soil(this includes the veg soil), the middle pot was too large (40cm round) but cost me £5 so it’s way underfilled.

Here a close-up of one of the bushy plants, pulled the fan leaves out of the way so you can see the nodes.
late veg

Critical Mass at Day 21

Just finished training my plants, so I topped the 3 best plants and removed the top set of fan leaves.

Here is a before and after picture, 2 small shoots(dead center) and 4 level shoots around the center, there’s also one set of shoots under the right and left large fan leaf, I have done the same on the 3 plants I have topped, just as I put the plants into flower I will take the best shoots and turn them into clones for my next crop.
before and after topping plant

Critical Mass at Day 28

So it has been 4 weeks since these Critical Mass plants popped out of the ground. I repotted them using my homemade flower compost today and I will be turning my plants over to flower tonight, as I don’t want them to grow too large.

Here is the flowering compost ratios I used to get the right ratio of NPK in flower:
Chicken manure (50g) 4.5 3.5 2.5, mg 1.0 cal 9.0
Bone meal (25g) 4.5 16.3 0
Westland Superphosphate (25g) 0 17.5 0
Potassium of sulfate (25g) 0 0 48

works out about 2.7(N) 8.16(P) 10.6(K)(125g) about 5g per liter.
Mix it well into 4lts of sharp sand then, then mix it into 20ltrs of Jacks magic compost, then mix 1ltr of perlite into the soil mix.

Top dress
seaweed (3 Tbsp) 3.6 4.8 4.1
fish blood and bones (3 Tbsp) 4 7 4
bone meal (3 Tbsp) 4.5 16.3 0
superphosphate (6 Tbsp) 0 17.5 0
potassium of sulfate (3 Tbsp) 0 0 48

2(N) 10.5(P) 9.3(K)
add this to 600ml of dry sharp mix well.(something like 0.6(N) 3.5(P) 3.1(K) cool top dress)
3 Tbsp per plant week 3,5,7

group picture
back right if I wanted 12 tops

Top view of the strongest plant
above view of strongest plant


Critical Mass – Flower Day 1

Lights were flipped over 7 days ago and they have started to stretch, node spacing is good but there really going for it. First white pistons are now visible so I will class this as day 1 flowering.
flower day 1
critical mass flower day 1

Critical Mass – Flower Day 7 (1 week)

The bud sites are starting to develop already. The growth over the last 7 days is on target, filling the flower room, they have all grown a good 4-6″ in height/width.
flower day 7 critical mass
flower day 7 critical mass

Critical Mass – Flower Day 10

They should stop stretching in around 4 days, well I really hope so LOL, the one in the back right corner has reached 2ft(above the pot centre pot).
The canopy has filled the room, need to spin the centre pot to give the plant a little more space, there is enough space between the shoots/plants and the canopy has a good amount of airflow, so I don’t need to thin the canopy out.

Here is a picture of the canopy
flowering day 10
critical mass flower site

Critical Mass – Flower Day 14 (2 weeks)

14 days since the white pistons first showed, the canopy has filled out, taking up all the space, and the stretching has slowed down, and all looking good at this stage.
critical mass 14 days in to flower
critical mass 14 days in to flower

Critical Mass – Flower Day 21 (3 weeks)

Day 17 in flower(12/12) and they’re still growing in height, just hit 30″
cm day 17
cm day 17 sites

Critical Mass – Flower Day 28 (4 weeks)

Some of the lower leaves had died off, humidity was getting too high(often spiking up to 75% and then back down to 60%), temps were between 20c and 23c. so I have installed a second heater to bring these up. I placed an oil radiator(500w) just outside the flower door(some air is pulled in underneath) and the temps have gone up to 25c and the humidity between 59% and 65%. Really I need the radiator in the flower room or another 3ft tube heater to get the temps up another 2-3c But overall everything is going really well.
critical mass 4 weeks flower site
critical mass 4 weeks flower

Critical Mass – Flower Day 35 (5 weeks)

critical mass 5 weeks flower site
critical mass 5 weeks flower
I am hoping to crop at 8 weeks so there may only be 3 weeks left to go at this point. The front left buds are the largest(earthy smell), and the back right buds are solid with resin and smell sweet and fruity.
So there is a good mix in this batch.

Critical Mass – Flower Day 56 (8 weeks)

critical mass 8 weeks flower site
critical mass 8 weeks flower
critical mass 8 weeks flower
So today is officially 8 weeks in flower but they definitely need another week, would be a shame to crop them right now as the final week packs on so much weight and changes the high. I will reevaluate in 1 week and see how they are looking.

Critical Mass – Flower Day 63 (9 weeks)

critical mass 9 weeks flower site
critical mass 9 weeks flower
So many fan leaves are turning yellow indicating the plant is coming to the end of its life cycle and is ready for harvest. I will begin harvesting tomorrow!


critical mass harvest
critical mass bud

All top colas were removed from 4 plants, It left a beautifully even canopy so I decided to let it continue to flower for 2 weeks.
The rest of the buds came down 2 weeks later, here are the pictures.

critical mass harvest
critical mass harvest


How much did Critical Mass yield?

So my total yield from 4 Critical Mass plants was 20 ounces dry. The LED bars used about 370w in total, flower room is 15ft2. So I pulled about 1.5g per watt. Not bad for a low-budget grow!

How long did Critical Mass take to flower?

This strain took 9 weeks exactly to flower and fully ripen.

How tall will Critical Mass grow?

These plants grew to 30 inches in height and stopped growing in height at week 3 in flower.

Was Critical Mass easy to grow?

This strain was easy to grow and there were no issues throughout the entire process making them beginner-friendly.

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