A surface skimmer is a really useful addition to any external filter
Amazon.com : Pool Skimmer Socks - Pack of 20 Fine Mesh Swimming Pool & Spa Pre-Filter Savers for Filters, Baskets, and Skimmers : Patio, Lawn & Garden
Ocean blue Widemouth Skimmer Box for Above Ground Swimming Pool Filter Systems from - Walmart.com
SunSun Hang On Filter Skimmer Up to 100 Liter Aquarium 6W Multi stage Filter Adjustable Flow Oil Film Remove 500L/H 20 80cm TANK|hang on filter|skimmer hang onaquarium filter sunsun - AliExpress
Surface Oil Protein Skimmer 300L/H JY 03 JY 02 3W 5W Aquarium Aquatic Plant Fish Tank Water Filter|skimmer 300l|protein skimmeraquatic filter - AliExpress