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Gardening Rhythms

Biosphere Light, CO2 and Water Cycles

Pholowko Friday 20 of November, 2015

Summary: CO2 levels have been averaging round 400 ppm.  It started around 800 ppm when the tank is first closed.  Three weeks have passed.  And the CO2 level dropped.  The water level in the two plant tanks is going down.  This means the soil is drying out.   Dry soil was originally placed in the tanks.  Here is a list of general observations:



  • The RH shifted from 89% down to 63% (Ave).

  • The tank temperature is around 25/20 degrees C (day/night).

  • CO2 averaged a little less than 400 ppm.  

  • Plants started to stall in growing because of the lack of water.

The system is re-opened and the air pump is installed for the marine tank.  The soil in the right tank is watered until it starts to shift over into the sand.  The plants in the left tank are watered and placed on sand.  The screen support system is removed.  


Mirrors are added to the left tank for light distribution.


Since no water can get in or out of the system, it is concluded that the water in the tank's air must have been consumed by the plant's growth as foliage or went into the soil.  As the RH goes down, the amount of CO2 goes down as well.  It is observed that plant growth slowed down.  It cannot be concluded that plant growth slowed because of the lack of water.  It can have slowed because of lack of CO2 too.  CO2 is also produced on the soil layer.  This sounds like an experiment on the side.  


 



Light States



Sun light hits the earth 24 hr/7 days a week.  This means CO2 is produced on the dark side and O2 is being produced by plants on the lit side.  As the earth spins around, the CO2 is mixed and is distributed all over the place.  The same goes for O2.  


Since plants grow at night, they off gas CO2.  That means in a small confined volume, something needs to be taking up the CO2 and producing O2.  In this case, two tanks are swapped back and forth with lights.  Two small fans blow air between all of the tanks.


State 1


BisoSphereState1


The center tank has its lights on for 12 hours.  The marine and left tank's lights are off.  The air pump continues to work all the time.  


State 2


BioshereState2


LED lights are OK for lighting.  They get hot and add heat to the system.  They need to be cooled for life extension.  They are point source of light.  That means light is always coming  from one point source.  Light does not go under the leaves and around in all locations.  Plastic mirrors are places on three of the four sides of each tank to help spread light.  The light from the LEDs are reflected to all sections of the tank.  This helps with efficiency.  



Current Trend of CO2



The CO2 trend is lowering.  When the RH is high and CO2 is lowering, it means the plant leaves are working consuming CO2.  When the CO2 is high after watering, (around 900 ppm) it means plants are growing new leaves, but they are not developed enough to keep a high flow of CO2 to O2.  


Since the system volume is very low, CO2 gets tipsy.  While learning how to become a biosphere farmer, it makes a difference how much volume of foliage exists in the system.  The plants need time to establish and grow before anything new is introduced into the system.  This appears to be the same steps nature took before four legged creatures appeared on the earth.


CurrentCO2 Biosphere 4


 



Internal Air Pump



The piston air pump is installed inside the biosphere.  Air from inside the tanks is pumped into the air stones on the marine water.  It is noticed that the marine water grows more phytoplankton when the CO2 is up.  It is currently getting more and more green.  


Air stones are a bad way to blow air into water.  They get plugged up easily with bacteria and dirt.  The chimney pumps are getting replaced with graduated cylinders with glass pipes as the bottom to let in water and to pressure air.  Are will be released through an opening off a 4 mm glass pipes.  Graduated cylinders are used because they have a natural stand at the bottom and an opening at the top.  The current air stones are beginning to plug up and block air flow.  Since biospheres are self-contained, it is important there is high equipment reliability.


Airpump Inside Biosphere 4



Water Cycle



The dehumidifiers are not pulling enough water out of the air to feed the plants.  More water is placed in the soil for initial starts.  It appears water needs to be monitored and controlled depending on the system's temperature and amount of foliage present on plants.  


Future Goals:



  •                  Monitor the amount of water for starting up a system.

  •                   Monitor the relationship between CO2, plant foliage and RH.

  •                   Increase the amount of general foliage in the system to balance out the night.

  •                  Increase airflow between the marine layer and the farming tanks.