co2 consumption in a sealed room

hi, I'm currently setting up co2 in my grow room for the first time, I'm using a controller, a reg and a co2 bottle. Well my 20lb bottle lasted 126hrs. Which seems incorrect. The room is sealed I read on here in one of the posts, to slightly ventilate the room as it sucks the heat from the ceiling considering co2 is heavier than air, I figured good idea with the added bonus of introducing some fresh air into the room in the event I run out of co2 during a cycle. When I didn't have the ceiling extraction fan slightly going I got 126hrs from a 10lb bottle, which still seems excessive. The plants are still small 3wks into veg so they shouldn't be consuming great amounts, the room is fully sealed so by rights it should hit the required ppm and than stop drawing co2. So how do I calculate how much co2 is required to elevate from 400ppm to 1200ppm in a sealed grow room with a grow room volume of 370cubic feet? the ceiling is 7.5ft high width 3.5ft length 14ft. The inlet fan and exhaust fan are fitted with flap valves other than that there are no other entry points that aren't sealed. For those who use co2 what are your consumption rates like? thanks in advance wilson

You buy a CO2 controller and stop guessing. Get one with fuzzy logic since you are using a bottle.

If you plan to ventilate then get a fully integrated environmental controller so the CO2 enrichment will automatically disable during vent cycles. If you just want to add CO2 control then this is a cheap way:

https://heavygardens.com/titan-cont...MI4ZfTxPyz5AIVFtNkCh3mkgAWEAQYAiABEgIEyfD_BwE

i have a controller with fuzzy logic

wilson2 said:

i have a controller with fuzzy logic

Click to expand...

Oh, I saw you were trying to calculate the numbers and figured you didn't have a controller lol. Sorry. There is a thread that has the info you seek, ill go find it.

i already used the calculator and as I dont know what my flow rate is, so it doesnt help. I put in 5cf/hr and was told it should last 35hrs

How are you controlling temperature and humidity?


I use a 6k window AC in my sealed 4x8x8. No venting. 20lb bottle of Co2, I get about 30 days of 1000ppm average during 12/12. 50pint dehuey.

thanks tint . given thats 360hrs of running your getting approx 18hr/ lb of co2 at 1000ppm.for a 256cf room
im getting 126hrs ....6.3hr/lb of co2 at 1200ppm for a 370cfm room with the exhaust running at 6%
I also got 126hrs... 12.6hr/lb of co2 at 1200ppm with it fully sealed. Considering mine is a 1/3 bigger and im using a higher ppm I guess it must be about right. I ventilate at night. I will have to stop venting while the lights are on. thanks again

Talking efficiency, I should also mention this is what my rooms are made of....
Technically far from being truly sealed imo. But it works well for my situation.

tint I have a 3.5k split air con in the room, I also use a humidifier. My room is fully sealed except for the inlet and exhaust fans which have spring loaded flaps. It is possible there is lose due to convection and air is passing the spring loaded flaps, I could try installing a motorized flap valve. The co2 controller runs off a light sensor in the probe, I think ill run it off a timer than I can shut it off before lights out.
I found a thread in another forum 420magazine threads/co2-and-you. sorry wasn't allowed to post link.
using the calcs a 20lb co2 bottle should be able to put 1200ppm into a room my size 380 times. Considering the plants are only still small there consumption would be minimal. I exhaust during lights out and only enter the room than. I don't believe I should be using this amount of co2. I'll let you know how I go after making the mods.