We Value Your Privacy

We and our partners use technology such as cookies on our site to personalise content and ads, provide social media features, and analyse our traffic. Click below to consent to the use of this technology across the web. You can change your mind and change your consent choices at anytime by returning to this site.

Update Consent
Loading ...

How to Install a Fluval 4 Plus Underwater Filter

Updated February 21, 2019

The company Fluval makes several different filtration systems for freshwater and saltwater aquariums. Filters pull water over a series of material such as charcoal and foam to extract debris and ammonia from the tank. This enhances the appearance of the aquarium and keeps your fish healthy. The Fluval 4 Plus is an in-tank filter used in aquariums that hold up to 57 gallons of water. To install the Fluval 4 Plus you only need to properly connect the hoses; no tools are required.

Loading ...
  1. Rinse the Fluval 4 Plus's foam pads with clean water. Insert the pads into the bottom of the filter and place the end cap on the filter body.

  2. Locate the suction cup bracket. This is a rectangular piece with two holes at the top and one hole at the bottom. Insert the three suction cups into the holes on the suction cup bracket.

  3. Insert the hose adaptor into the filter's water outlet. The water outlet is found at the top of the filter. The hose adaptor is a small tube of plastic with a nozzle hole in the centre. Position the hose adaptor so the nozzle hole faces upward. If laying the filter on its side rather than standing it on end, plug the nozzle hole of the hose adaptor.

  4. Insert the air control device into the nozzle hole. If standing the filter on end in the tank, the air control device goes into the nozzle hole in the centre of the hose adaptor. If resting the filter on its side in the bottom of the tank, insert the air control device into the end of the hose adaptor.

  5. Attach the suction cup bracket onto the back of the filter. Place the filter in the tank. Position the filter so the water outlet is at least one centimetre below the water's surface and the air control valve is above the water's surface. If laying your filter on the bottom of the tank, attach a piece of tubing to the air control valve. The tubing needs to be long enough to reach and stay above the water level of the aquarium. Press the suction cups to the glass to hold the filter in position.

  6. Plug in the filter and turn it on. Move the water outlet to change the direction of the water flow. Move the water flow adjuster to control the flow rate of the water.

  7. Tip

    Clean your Fluval 4 Plus system at least every two months.


    Unplug all electrical items in the tank before sticking your hands in the tank. Do not plug in the Fluval 4 Plus until you have it installed. Do not run the Fluval 4 Plus unless it is immersed in water.

Loading ...

About the Author

Tammie Painter

Based in Portland, Ore., Tammie Painter has been writing garden, fitness, science and travel articles since 2008. Her articles have appeared in magazines such as "Herb Companion" and "Northwest Travel" and she is the author of six books. Painter earned her Bachelor of Science in biology from Portland State University.

Loading ...
Loading ...