I have read a little on DIY CO2 injectors, and want to make one when I
eventually buy an aquarium.
I read that the tube from the plastic bottle is connected to the intake tube
of the filter.
Will this not pull the yeast/sugar/water mix from the bottle into the
filter?As I was thinking of buying a canister type filter

How exactly is this DIY CO2 kit setup?

Thank you for any help you are able to give .