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I have a fancy new grow setup that I have been building in my new place and this grow is the first to try and see how CO2 enrichment goes. I'm an engineer by trade so the building of the set up is half the fun.
I wanted to hit the seedlings as early as possible with the benefits of CO2 enrichment - which of course then requires a steep elevation in light intensity and also ambient temperature to bring the benefits of a faster growth rate. The seedlings did not react negatively to the sudden increase in light intensity - I think many DIY growers coddle seedlings too much.
1) Seeds were placed pointy end down into dry growdan cube.
2) Cubes were placed together and wrapped in aluminium foil (this prevents light leakage and keeps them moist)
3) A small amount of calmag was added to about 500mL tap water (my tap water is too soft otherwise), and this preparation was poured over the cubes until saturated
4) The foil was then sealed and placed on my wifi router for incubation.
5) The first 3 seedlings emerged after 36 hours, and these were placed under gentle diffused window light
1) After 2 days of gentle light, all seedlings/cubes were planted into their net pots with the clay pebbles and placed under metal halide (15000 lux)
2) After 24 hours under MH, CO2 enrichment applied and intensity increased to ~55000 lux (60% RH, 29 deg C)
3) Solution swapped to week 1 vegetation as per Canna nutrient guide (roughly 600 ppm) after cotyledons showing signs of depleting magnesium (not a problem but figured they showed that they needed some nutes)
End of week 1 - all seedlings strong and vigorous. Some mild nute burn (or maybe heat stress) on tips of 1st leaf set, probably due to excess calmag during early days or very intense light, however, second leaf set are looking happy. First 3 are a little stretched as they were held back to wait for the laggards to emerge.
Put into the DWC half way through the week. Some unfortunate splashing of nutrient on the leaves caused burning, but otherwise they're growing strongly.
Only 5 days - not a full week before flipping to 12/12. Put into flowering positions and adjusted lights. Ready to put up netting / vertical scrog. Changed to 2x600 watt HPS as plants are getting too big to maintain sufficient intensity with only 1 light.
The leaves and stems are insanely big, I'll make sure I'll get a photo.
The only variable that isn't optimised at the moment is reservoir temperature. It's higher than optimal at around 28-30 C, but I have heaps of circulation and bubbles, no light leaks, and Cannazym is an amazing product.
Crazy growth again this week. Topped up nutrients and water twice this week - 25 litres first time and 20 L second time. This is in a 70L total volume DWC, so you can see how much they are drinking AND feeding. The EC has been dropping slightly between these top-ups which indicates that they are eating as much as they are drinking. No clawing or yellow tips give me further confidence in the nutrient/pH mix.
Hot reservoir (27-31C) isn't seeming to be an issue, but I guarantee you if I stopped with dosing ~20 mL of Cannazym each 2-3 days it would become brown'n'stinky (don't add the full recommended dose in one go, spread it out).
Tiny little pre-flowers appearing, but no pistils. Someone help me relax about the lack of pistils, please.
This week I changed to flowering nutrients after seeing the first pistils (yay!). Seeing the pistils is a milestone IMO as it confirms two things a) female plants and b) plants are responding to photoperiod change.
The most obvious outcome was the absurd 55 cm of growth in a week. That's 7.8 cm a day. I guess that's what happens when CO2 and DWC are combined with very intense light. They drank and ate proportionally to their growth (lots!).
I'm pretty relaxed right now as they are looking very healthy and are developing lots of lovely bud sites. My 2 concerns are keeping the lights far enough away, and supporting the branches as they get longer for future heavy buds.
A very stressful week. Found some balls (male flowers) on one of my plants an panicked and chopped it down. Subsequently I noticed some balls on a few other plants and fell into a deep depression. Why did my plants feel so confused? They had a very luxurious life, living without stress. Some users felt that it was a genetic trait, however, laws of probability indicate that since I had multiple plants go hermie it's more likely a stress incident. I think I may have gone a little too much with the Cannaboost, which is a flowering stimulator and I assume capable of causing some hormonal stress in the plants.
I inspected the plants for balls twice a day (lol). Removed any I found and after a couple days they didnt reappear. Kind of annoying that I chopped 1 out of 5 plants, but at least I learnt something.
They are looking very lush at the end of the week, exploding in flowers.
Flowers properly growing now. Getting rather frosty too/ Sticky. Smell has evolved into candy-sweet fruity aroma, and I definitely will need to start the carbon filter soon even though it's a sealed room ;)
Boost week - added PK booster. Flowers getting fat now. Unfortunately I've given them a touch of nute burn, some burnt tips but everything else is looking lovely. Getting sticky and frosty.
Big mass gains. Experiencing "The Sag" - flowers gaining mass and sagging down, so I added some yoyos to support some offending branches. I definitely will do proper scrog screen for all plants next time - the plant that has the screen over it is behaving itself and not dropping all over as it gains mass.
The flowers are starting to get a bit of purple/blue colour to them, which is really nice. Looking good. I'd like the smell to be a bit more intense (hence the CMH), but then again I have a brand new carbon filter going so it could just be that.
Backing off on nutrients and CO2 in the last few weeks now. I have swapped the HPS for CMH (4k) to get some more density and terpenes in the last few weeks. I'm also hoping the additional blue and UV light from the CMH gets them a little frostier too, but they're already real sticky so I'm just being greedy. The plants seem to really grow towards the CMH much more than the redder HPS. The HPS would have them all growing more or less vertically, whereas the CMH causes them to grow towards the light. This makes some plants fight each other so I've had to put in a couple horizontal yoyos too.
Entered the final phase of flowering. I made a strong reduction in nutrients when I refilled the reservoir. Switched the CMH 4000 K to 10000 K finishing lamps for higher UV and blue to get some more terpenes and resin. Reduced humidity and temperature.
Wanted to fully cure and smoke a fair it before I reviewed.
Super frosty and very productive plants. The aroma and taste could be a little stronger, but that might be the indoor/hydro aspect. Strong pain relief and physical relaxing effects, true to form it does not have that couch lock effect (although I did harvest slightly early as I do not like really knock out indicas). It did unfortunately lend itself to an introspective mood which could sometimes make me melancholic; its not a social strain.
The slight hermie issue I had early on in early flower has only resulted in about 5 seeds across 300 grams. I conclude now the stress was due to excessive floral booster in the nutrient mix.
My mate decreed this the best weed he has ever had, so he likes it. However, it is probably a little too on the indica side of stuff for my preference. Glad I grew, but probably won't grow again.
sloppyjohn
