Pond Foam Filter Media Pack (Set of 3) 25" x 18" Coarse, Medium and Fine. Finest-Filters Set of 3 x foam filter pads are ideal for all pond filters. This set contains 3 x foams. (Coarse Black, Medium Beige and Fine Blue). These filter foams measure 25" x 18", and have an egg-crate profile on one side to effectively catch waste from the water. Simply cut to size using scissors. Our filter foam is totally aquatic safe, and is not treated with any chemicals, so it is guaranteed to not harm your fish. All of our reticulated pond foam is manufactured to the highest quality. Available in three sizes - (11" x 17", 25" x 18" and 42" x 21") This set size is 25" x 18".