I mostly kept DIY CO2 as long as I needed to get the money to buy a pressurized system, not to say plants do not benefit from the extra CO2 added this way. If you want to go the yeast route, connect 2 bottles started at a time difference. Put a one-way valve on the setup so as not to get water from the aquarium in the bottles. Do not overfill the bottles as sometimes foam forms on top and can get into your aquarium. Never pressurize the bottles ( stop the CO2 flow). 1-3 days at the start of a new bottle you will get a spike in production depending on the temp., keep an eye on your fish at that point.
Since you have to deal with low pressure, low production CO2 I recommend using a reactor if you have a canister filter. Otherwise, use a powerhead that can break down the bubbles into a fine mist. Atomic /ceramic Diffusers do not work well with DIY yeast CO2 reactors.