Sponge or any air driven filters are great, you can also use any filter rated for your tank as the ratings are always wrong as long as the filter has the ability to be dialed down. So a filter that says rated for 10 gallons and you have a 10 gallon and the filter has adjustable flow. Keep it on the lowest setting. Using live plants is also great in a ADF tank. There are many easy low maintance plants out there.