Using this Oase BioStyle Power External Filter is easy. First, use the adjustable leveler to secure the filter to the rim of your aquarium up to 30 gallons. Adjust the telescopic intake according to your needs. Plug in the motor and start it. You can then adjust the flow control to get the right water movement and oxygenation for your fish. As for maintenance, keep an eye on the cleaning indicator. When it shows it's time, replace the disposable filter cartridge. Remember, this filter works with both fresh and marine water. Since it's UL certified, you can use it with confidence. It comes with a 3 - year warranty, so if you have any problems, contact the manufacturer. Always keep the motor area dry to ensure it runs quietly and smoothly.