Some of the new protein skimmers on the market are multifunctional and have room to make them wet dry filters in addition to protein skimmers. The most versatile units are the supreme skilter, and the Via Aqua multiskimmer. Both have chambers where you can put bio media like ceramic rings or bio balls and can make them multi use as both wet dry and protein skimmer.Both units are economical under 100.00 dollars and with the addition of bio media can be made into hang on wet dry skimmer units for smaller reef or saltwater aquariums. (under 80 gallons) Just pickup one of these models and put bio media in the extra space, hang them on your aquarium and put established bacteria in them and they are capable of supporting reef life with low cost.To make them low maintenance I recommend you buy and internal prefilter(goes in aquarium and pulls out debri and fish waste)and then you will have to clean them very little.