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BioBalls Versus Lava Rocks

BioBalls Versus Lava Rocks

With an assortment of filter media out there in the pond world from filter pads to bio-ribbon to lava rocks to bio balls. The purpose of your filter media is to house billions of beneficial bacteria and other microorganisms that keep your pond alive, crystal clear and algae-free. Let's take a look at the lava rock versus bioballs debate.

Lava Rocks

Lava rock – the igneous rock that forms as an erupting volcano's molten lava cools and hardens – is very porous. When chunks of it live in your filtration system, you provide a lot of surface area for beneficial bacteria to colonize and grow. That's what makes it such a great filter media.

It does have some drawbacks:

  • Clogged Holes: Over time, the porous rock can become easily clogged with muck and debris. Once the holes and pockets are clogged, they can become very difficult to clean out – which ultimately creates less overall surface area.
  • Hard Water: Lava rock naturally contains a variety of minerals, including iron and magnesium, that could affect your water's pH, making it harder. Hard water can make it more difficult to treat algae blooms.
  • It's Heavy: They may be porous chunks of rock, but hefting bags of it takes some strength – particularly when its wet and full of gunk.


Bioballs, like The Pond Guy BioBalls, are plastic spheres made up of dozens of thin rods that provide plenty of surface area for beneficial bacteria to thrive. Two hundred of the bioballs in a Mesh Bag will filter about 1,000 gallons of water in a pond with a minimal fish load.

Compared to lava rock, bioballs have some definite benefits.

  • Easy to Clean: Bioballs can also become clogged, but they are easy to clean. Just rinse them off with water from your pond and you will be good to go.
  • Indefinite Lifetime: Because they are made from long-lasting material, bio balls will not degrade and will function equally well year after year.
  • Shape Shifters: The round shape allows bio balls to easily conform to any filter, no matter its shape.
  • Lightweight, Easy to Handle: Each one of the tiny, 1.5" plastic spheres weighs a scant 0.3 ounces; 200 of them weigh a whopping 3.5 pounds. They are easy to deposit and remove from your filter thanks to a mesh filter bag.

Good filtration starts with good media. When starting your pond in the spring and periodically through the season, make sure to check all types of filters are in good working order. Doing so will save you time, hassle, and money because you will stay ahead of any potential problems and avoid dealing with insufficient filtration.