let me had my 2 cents because i think about this sealed room thing for some years
i will not talk about bottled co2
i will try to explain why judaz and others get better result by addig fresh air regularly
and why their plants can show problems with the burner on if the room is totally sealed
i'm no chemist but i think its easy to understand
co2 generators can burn propane or methane (natural gas) to obtain water vapor, co2 and heat
here is the balanced reaction for natural gas(CH4) complete combustion
CH4 + 2 O2 ----> 2 H2O+CO2
which means one molecule of methane need 2 molecules of dioxygene to generate 2 molecules of water and one of CO2
then the plants will use the co2 for the photosynthesis
View attachment 992945
we see that the plants will use 6 co2 to give 6 dioxygen
they dont give more oxygen than co2 ..
fresh air contain around 21 % o2, if the only o2 source in your room are your plants then its easy to see that a o2 deficit will be created by the burner
the burner will start to burn yellow and emite poisonous gas (carbon monoxyde..)
plants get sick
how to counter act this ?
-introduce fresh air constantly, just enough to keep the o2 level monitored over 20 % in the room
best way is to do a closed loop with a lung room. Inside the lung room the cooling system, dehumidifiers, co2 burners with a fresh air source near to allow a clean combustion
everything sucked and distributed to the main room before being sucked again to be retreated
or by using the crac systems, or some kind of rooftop unit that allow a percentage of air to be renewed during the cooling(rooftops usually do this).
or
-by adding hydrogen peroxyde (h2o2) frequently to the roots with a res outside the room, and a pump with PC drippers to water everything evenly
choose a fast draining medium that allow to multishot everyday
(thats my favorite because it allow you to run 100 % sealed)
keeping a level around 50 to 100ppm max of h2o2 in the main reservoir seems to correct the problem of lack of o2
its few, around 2.5mL per 10 liters of solution
it keeps the res clean as source water and oxygenate the room every shot
every run off of the room (AC/dehumidifer condensation water, rockwool runoff)come back in the second reservoir
there h2o2 level is monitored with h2o2 strips (0-100ppm)
1 part soft water nutrient is added until the right ec is achieved
ph is set ( sometimes not necessary) and everything is sent back in the main reservoir
no waste, and each watering get a large runoff that cancel any risk of salt buildup (used to be a problem for me in run to waste setups )
it can be a good idea for a sealed room grower to invest in a o2 meter
for growers using liquid propane burner, its a good idea to use a filter before the regulator to filter some contaminants inside the gas ( oils...)
if a chemist is around i would be happy to ask him a few questions
peace guys
