Drinkwell Original Pet Fountain for $20.39. Shipping is free on orders over $35. If needed, use this Filler Tool to pad the order for free shipping. Here is a screenshot for your reference. This pet fountain feature patented, free-falling stream aerates the water with healthful oxygen and an activated carbon filter removes bad tastes and odors. It holds 50 ounces of flowing water. Most places have it for about $33.