C02 Going Fast

I have been buying the 100lb co2 tanks My room is 5x8x8 I do not have a ppm meter but I run 1.5 cfm in a sealed room but its only lasting 2-3 weeks I know this cant be right could the gauge be bad or shoulld I run lower cfm

check for leaks between reg and tank had this happen in my kegorator I had it a hair to lose and lost 1/2 tank in a week

Get a meter to start. Air cooled lights almost always leak. Portable in room AC also pull air out of the room. Check to see if you have even the slightest neg pressure in the room.

you are leaking or spraying it all on the floor in excess. you need a proper ppm meter atached to a regulator if you want to maxmize your c02. 20lb bottles in near identical space as yours under 2000 watts last 3-4 weeks while spraying 1500ppm. something isnt right bro, id start with leaks but i bet you its the lack of a proper co2metering equipment. foil tape is great for sealing hoods and it can take the heat. good luck

smoke test/soap everything . spray soapy water on all co2 connections
smoke test whatever air cooled lights used to make sure no leaks, fix with silicone or something

1000-1100 PPM of co2 is ideal, and remember, co2 is heavier than air, so its going to sink