Fluval Betta Moss Ball

The Fluval Betta Moss Ball does two jobs at once. It looks like a tuft of moss sitting in the tank, and inside it is chemical filter media that traps phosphate, the nutrient behind most nuisance algae. Fluval sizes it for aquariums up to 20 US gallons, and the surface is soft enough that a betta's fins will not catch on it. Browse the rest of our aquarium decor.

What It Does

• Traps phosphate. Fluval calls it a 2-in-1 decorative piece and phosphate reducer, so it works as chemical filter media while it sits there looking like a plant.
• Safe on betta fins. The naturally soft texture is meant to protect delicate fins, which is the point of putting it in a betta tank rather than a hard ornament.
• Covers up to 20 gallons. Fluval rates one ball for aquariums up to 20 US gal / 75 L.
• Freshwater. The package is labeled for freshwater fish aquariums.
• No setup. Drop it in the flow. There is nothing to rinse, charge or assemble.

How to Use It

• Place it where water actually moves past it. Fluval's direction is to position it in the path of water movement, since media only works on the water that reaches it.
• Replace it every two months for maximum effectiveness. Like any phosphate media it stops adsorbing long before it looks used up.
• In a betta tank it doubles as a resting spot, so a betta that likes to perch will often sit on it.

Specifications

Pairs Well With

• Fluval Moss Ball, the larger non-betta version of the same idea.
• Fluval Betta Premium Aquarium Kit if you are setting the tank up from scratch.
• Fluval Bug Bites Betta Formula to feed what lives in it.
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Frequently Asked Questions

Is this a live marimo moss ball?
No, and this is the thing people get wrong. It is a synthetic ornament with filter media inside, which Hagen's own catalog lists as a plastic plant. A live marimo is an algae colony you keep alive; this one you replace every two months like any other media.

Does it really pull phosphate out?
That is what Fluval sells it as, and the package says it traps phosphate. Treat it as a small assist in a small tank, not a replacement for GFO in a big system.

Will my betta bother it?
Most bettas treat it as furniture and rest on it. The soft surface is specifically meant to avoid tearing fins.

How many do I need?
One covers up to 20 gallons per Fluval. In a 2.5 or 5 gallon betta tank, one is plenty.

Do I rinse it first?
No preparation is called for. Put it in the flow and leave it.