Ahh ok one thing with Diy CO2 setup's is they are almost never the same while most will use re-purposed soda bottles with the logic that they can contain the pressure I have found that that exact attribute is more of a detriment since they do tend to flex quite a bit and can lead to rather inconsistent results (it will work if it's all you have) When I ran the Diy setup I used 50-60oz juice bottles from one of the big box stores and that worked great the plastic doesn't tend to flex nearly as much and it allows for more consistent results. Another weak link in the chain so to speak is the quality of the yeast and how much dies off due to the water being to hot and if you mix a small batch in say a cup of water that you then add to the main bottle after the yeast has been activated.
IMHO I think lighting and Diy CO2 work very well together and can really cause your plants to go into overdrive in terms of growth just make sure you add in Ferts into the water column or the substrate or both or it's not going to last very long as the plant will exhaust all the nutrients in the tank.
By they way as said above an air stone is not the best choice for CO2 I've used lime wood air diffusers in the past with good results made very fine bubbles that got even smaller before hitting the surface of the water, but directing the flow into the intake of your filter is a good way to assure 100% absorption,