blue-green algae

Will a Canister Filter Help With Algae Control?

In Aquarium Filtersby PaulK

A canister filter can help control algae growth in an aquarium, but it’s not the cure. Algae tend to grow in stagnant water so the better the water flow, the less algae will have a chance to grow. Canister filters create better water flow in your fish tank and if you use a canister filter with a wavemaker, that will create even more water circulation.

Another good thing about canister filters is the fact you can put in additional filtration for phosphates that will help control algae growth. Power/hang-on-the-back filters are rather limited to the three main types of filters and not much else.

Ways to control algae

  • Minimize the light time on your aquarium by using a timer. Lights should only be on for 8 hours max.
  • Create a water flow with a canister filter and/or wavemaker in your aquarium.
  • Have live plants in your aquarium and keep them healthy! You may need CO2.
  • Minimize phosphates by using a phosphate filter.
  • Keep your aquarium away from direct sunlight.
  • Get some algae eating fish like small plecos or siamese algae-eating fish (not the Chinese algae eater).
  • Keep your tank clean by frequent water changes and substrate vacuuming. Algae feed off of uneaten fish food and other organic waste.

You may consider getting a hang on the glass algae filter like the HOG 1.3. It’s specifically designed for algae to grow on keeping it from growing on your fish tank.

If you have a green algae problem where your water is green, you may want a UV light like this SUN Jop-01. It really does the trick!

How the canister filter works:

A canister filter is a separate unit with a pump motor and the three forms of filtration that sit outside the aquarium. Usually underneath the aquarium to take advantage of gravity. The intake tube sucks water from your aquarium into the filter unit. The water flows through the filters and back into the tank via the return tube.

The intake tube and the return tube can be placed on opposite sides of the aquarium which creates the water circulation. There are different types of output mechanisms that canister filters have, such as a spray bar, jet return, or lily pipe.

How a wavemaker works (also called a powerhead):

A wavemaker is simply an underwater fan with a small motor that creates circulation much like a boat motor. You can get them in different sizes depending on the size of your tank. The purpose is to drive water toward your filter intake.

Benefits of using a wavemaker:

  • Surface agitation for oxygenation of the water.
    Circulation of the aquarium water so debris can’t settle.
    Skims the substrate kicking up any debris that does settle.
    It helps curb aggressive behavior in certain species of fish.
    Better water circulation equals less chance for algae to grow.
    It helps with live plant growth by circulating nutrients.

This Hydor Koralia on Amazon is very quiet, pretty cheap, easy to mount, and uses very little electricity.

The way to mount them is to put them on the opposite side of the fish tank than your filter intake. Some are adjustable so that you can tilt them up or down for surface agitation or kicking up debris from your substrate.

Do you need a wavemaker?

Not necessarily. If you have a big enough canister filter like this Fluval FX4, it’s probably sufficient to create good circulation in your aquarium.

Also, certain species of aquarium fish don’t like high water flow. An example would be betta fish.

You don’t want a wavemaker that’s too strong or you’ll freak out your fish!

Where to place a canister filter

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