The easiest way to do this is to scale it up a bit...like to a 5gal bucket, and use tubing to run from the top of the bucket, running all the way around the canopy of your plants. You want to cap off one end however you can, and poke very small holes in the tubes. Also, you will need to be sure the tube fits air tight in to the lid of the bucket. Silicon caulk works well. I usually use a lighter to melt the end of aquarium tubing and pinch it together, and then I use an all (looks like a screwdriver, but it has a sharp, tapered, point rather than a flat or cross head on it) to make the holes. If the holes are small enough, you will get CO2 through all of the holes from beginning to end.
Alternatively you can use slightly larger tubing, and slightly larger holes, and put BOTH ends of the tube in to the bucket. You have to be careful when doing this though, because if the gas is not able to escape fast enough through all of the holes you made, then pressure will build up and either blow the top off of the bucket, or blow the tube out of the lid...either way, IT CAN BE MESSY! DON'T LET THIS HAPPEN!
You can tell pressure is not building if you can feel the CO2 coming out of all the holes with little pressure. If you feel a sharp, fast stream of the gas coming out of the holes, then make the holes bigger, make more, or even add another tube.
If you can't feel gas escaping from the holes toward the end of the tube, then you made your holes too big or made too many.
It will take time for the CO2 production to reach its peak, so you would just need to check on it from time to time to adjust the number or size of the holes or number of tubes you're using.