Maxi-Jet PH pump and power head is ideal for powering undergravel filters or creating internal water movement from its fully rotational output. The Maxi-Jet PH incorporates a venturi aeration device to provide optimal aeration and gas exchange in the aquarium. A silencer keeps the venturi aeration device operating quietly. An adjustable air filter permits the user to fine-tune air volume and water mixing as desired. The intake tube adapter with prefilter screen prevents gravel or loose material in the aquarium from getting into the pump.