Aquarium powerheads or wave makers are used to create flow inside your aquarium in addition to a sump or return pump.
Wavemakers can be used to create waves inside your aquarium, and are a great way to keep detritus from building up in your rock or sand. Wavemakers or powerheads play a vital role on water quality and conditions of livestock. Most fish and corals will thrive and do much better in higher flow aquariums, with the exception of seahorses and pipefish. Most reef tanks require a huge amount of flow when keeping live corals and fish, having a large wavemaker or controllable pump can help the protein skimmer export waste. Using a wavemaker like the Vortech pumps by Ecotech can keep the detritus in the water colum so your filtration can take it out, giving you a cleaner tank and less nutrients.