Back at the end of March, I made these bubbler systems from 10 gallon buckets:
wrapped them in insulation, made little holes in the lids, and inserted net pots
containing four chili plants freshly rooted in a Rainforest propagation
system. My original plan was to perform a test on supplying dissolved oxygen in
four different ways. However the two plants at the back quickly fell behind,
got crowded out, and well, it was quite a while until I discovered they were
actually, yeah, how do I say it? Dead, yes,
dead. Dead as Dodos fastened to doors with nails. Suffice to say the dissolved
oxygen experiment needs to be reviewed and repeated, at the very least. However,
today, I have entirely the opposite problem. Despite now only having two
plants in this 4x4 grow tent, they have grown, and grown, and grown. One conclusion
I am able to tentatively draw at this point is that my air pumps and air
stones are doing a great job of supplying oxygen to the nutrient
solution. I'm using an Eco Plus "Eco Air" twin-outlet air pump to bubble air into
both buckets via some air-line. One via an Eco Plus air stone, and the other with an
Eco Plus flexible air diffuser pipe. The Eco Air 2 pumps 126 gallons of air per hour
and I'm effectively aerating 20 gallons of nutrient solutions split over 2
buckets, that's 6.3 gallons of air per hour per gallon of nutrient solution. I
should point out that this is a bare minimum; you can go much higher. I know
some of the water culture specialists out there recommend up to 16 gallons of
air per hour per gallon of nutrient solution. If you're a metric person then
think 1 liter per minute for every 4 litres of nutrient solution, but don't
get too much higher than this or you risk creating so much turbulence in the
nutrient solution that you could physically damage your plants' roots. You
can also get air discs, and micro bubble air diffuser rings, and diffusers too,
that create smaller bubbles for more effective aeration with less turbulence.
I'll be checking those out in a special video all about dissolved oxygen soon.
But, now I need to figure out how to stop my chili plants from growing, and get
them to start flowering and fruiting. This is easier said than done. My peppers
are from the tropics: the Dutch Antilles in the Caribbean to be precise. And as
such, they don't respond to the changes in photoperiod. So, simply switching my
light controllers time to a 12-hour cycle isn't going to cut it. My grow
light is a Sun Par 300 watt LED with a wonderful bloom spectrum to emulate the
output of an HPS, but, and here's a thing, just because it's got a spectrum
that's awesome for flowering plants, doesn't mean that it'll actually
initiate flowering. That's down to the species genetics and other environmental
factors. It turns out the plant staying vegetative for too long is all too common
to many indoor gardens. Conditions tend to be warm and sheltered, making plants
favor growth over bloom. However, if we don't get the balance right, it's all too
easy to end up with lots of stem and leaf, and precious little fruit
production. Light levels, as you can see, are up in the 500 + micromole zone. This
should be sufficient for my needs, and note how I've got the Sun Par attached
directly to the cross beam of the Sun Hut Blackout grow tent, so I have no
wiggle room left if my plants get any taller. "What about my beloved soft mesh
netting?" I hear you ask. Well that's all the way down here, doing pretty much
nothing to help my cause. I can't increase the time between irrigations in
an effort to create a drier root zone, as the roots are constantly submerged in
nutrient solution. If I were growing in soil, coco coir, stonewool, or some
other substrate, then this would be an option. Dryer root zones cause a mild
stress that helps to steer peppers into flowering and fruit production. I was
able to keep the same plants in Grodan Delta 4 inch blocks far squatter
using this technique. I can't decrease air temperature, as I'm
up in my attic in mid summer, with no air conditioning. What was I thinking. I'm
running my Sun Par at night when ambient temperatures of the coolest. Of course,
lights-on temperatures are at around 82 degrees Fahrenheit, or 28 degrees Celsius.
Now, if I could create a bigger difference between my daytime and
nighttime temperatures, say using air conditioning to reduce my nighttime
temperatures to 60 to 64 Fahrenheit, then that would definitely help cue my
peppers to start flowering. Now, relative humidity remains low, around 20 to 30%,
and this actually runs in my favor. Harsher higher VPD conditions help
to stimulate generative production: flowers fruits and seeds. High planting
density can also keep planes vegetative, but while these two pepper plants are
certainly doing a good job of filling out the tent, the conditions aren't too
cramped yet. Note how the plant on the left is
starting to flower, but the plant on the right is full-on still in vegetative
mode. That's because I'm still chilling the nutrient solution in the bucket on
the right down to 66 degrees Fahrenheit, around 19 degrees Celsius. A hangover
from my dissolved oxygen experiment. Whereas the bucket on the left is
unchilled at 75 degrees Fahrenheit, or 25 degrees Celsius. A cool nutrient solution,
while great for root health and dissolved oxygen levels, can actually help keep
plants vegetative. So what am I going to do?
Well, the first thing I'm going to do is prune back some of these growth tips.
I'll use this opportunity to take lots of cuttings as I love having a stock
from the same mother plant for my experiments. And this also serves as a
quick fix at reducing the plant height, especially this plant here on the right.
I've seen some growers prune canopy-level leaves at the beginning of
flowering, claiming that it helps the plane to focus on buds, flowers, and fruit
production. I do not recommend this! Those leaves are
important for absorbing the very light energy needed to actually power
generative development. Number two, I'll increase my nutrient solution to 800 PPMs.
Using Flora Series 3 part. I'll use equal parts of grow, micro, and bloom for now.
And once the flowers start to develop, I'll up the bloom component and lower
the grow. This is a strong nutrient solution for water culture and should
mildly stress the plants into flower and fruit production. Number 3: I'll set my
nutrient chiller to 75 degrees Fahrenheit. Number 4: I may invest in a
portable air conditioner, just to help me keep nighttime temperatures low.
Hopefully, by the time next summer arrives, I'll have a permanent air
conditioning solution installed. Now, let me know your thoughts in the comments. I
won't be using any exotic stimulators or PGRs, as these are consumable crops, and
I always like to grow without them anyway. I hope you enjoyed watching.
Please hit that subscribe button below, as it helps keep me hard - I mean
generative, generative. This is Everest, all vegged out. Bye-bye.