what c02 controllers do you recommend?

Hi there. I know a lot about co2 in my short run I have cut my growing time down as much as 70% just in the seedling stage into the veg state. 4 days and i left the seedling stage. Also even if you aren't using it for co2. You know when you hit your DLI as co2 intake stops completely in ambient conditions. So, even without co2. I've learnt so much One of the best controllers on the market that is the not crazy expensive.. You'll pay 300e for the controller that has a sec by sec reading. And you'll need to buy a Reg (BTW, the reg is bog standard ALL the top co2 controller makers use the same reg with selo valve, vivoson) you'll get 1 for 40e Pro leaf. The cheapest place i could find it in the eu is led grower eu