dwc pump question

new at DWC. just wondering what size pump to get for a 5 gal bucket. i picked one up and set it all up and it just doesn't seem to me that it's producing enough bubbles. picked it up for $15 at wally world. it says it's for a 10-30 gallon aquarium.

Doesnt matter what size the bigger you go the more bubbles you get .. The More bubbles you get the better ...

As long as it delivers the nutrient solution to it at the proper times and efficiently..Want more bubbles get a bigger airstone and pump.