Fluval Biological Aquarium Cleaner
Pack size
120 mL
Cost per litre
1.9c
Water type
Freshwater + Marine
Pack size
250 mL
Cost per litre
1.5c
Water type
Freshwater + Marine
Pack size
2 L
Cost per litre
1.0c
Water type
Freshwater + Marine
Fluval Biological Aquarium Cleaner
A weekly top-up that keeps gravel, media and glass from building up waste between full cleans. Fluval Biological Aquarium Cleaner adds a dose of waste-digesting biological activity to the water column, working on the organic debris that settles in gravel, power filter media, ornaments and glass rather than requiring you to scrub it all out by hand. It's sold in 120 mL, 250 mL and 2 L sizes, from a single tank up to a fish room.
Why you need one
Aquariums generate more waste between water changes than filtration alone clears – uneaten food, plant debris and fish waste settle into gravel and cling to decorations and filter media. Left alone, it breaks down slowly and can dull the tank's appearance. Biological Aquarium Cleaner is formulated to speed that breakdown along, cutting down on how much manual scrubbing and gravel-vacuuming a tank needs.
Key features
- Targets four zones – gravel bed, power filter media, ornaments and interior glass.
- Weekly dosing – designed to be added regularly rather than as an occasional deep clean.
- Fresh and saltwater safe.
- Pairs with Cycle Biological Enhancer – Fluval recommends dosing the two together to help manage any ammonia rise as waste breaks down faster.
- 2 L pump bottle – each pump dispenses 5 mL, useful for larger systems dosing often.
Specifications
| Sizes | 120 mL, 250 mL, 2 L |
|---|---|
| Format | Liquid, dosed into aquarium water |
| Water type | Freshwater and saltwater |
| Application areas | Gravel, filter media, ornaments, glass |
| SKU (120 mL) | FLS16 |
| SKU (250 mL) | FLS17 |
| SKU (2 L) | FLS19 |
Dosage and directions
Fluval recommends dosing at least weekly for ongoing maintenance. During a partial water change, dose for at least the volume of water changed. Fluval doesn't publish a fixed millilitre-per-litre ratio for this product and states it can't be overdosed, so err on the generous side rather than measuring precisely. The 2 L bottle dispenses in 5 mL pumps, which makes repeat dosing on a larger system quicker to measure out.
Fluval hasn't published a specific ingredient or active-constituent breakdown for this product – check the bottle for the current formulation if that detail matters for your setup.
Suitable for, and not suitable for
Suitable for established freshwater and saltwater aquariums as a routine maintenance dose. Not a substitute for water changes or gravel vacuuming, and not intended as a spot treatment for an existing ammonia or nitrite spike – for that, a partial water change is the faster fix.
Goes well with
Fluval Biological Enhancer – Fluval recommends dosing it alongside this product to help manage ammonia as waste digestion speeds up.
Warranty and delivery
Covered by Fluval's standard consumer guarantee against manufacturing defects, in addition to your rights under Australian Consumer Law. Standard freight class.
Common questions
Will it cloud the water?
No – it's designed to be dosed into a running tank without causing cloudiness.
Can I use it in a shrimp or planted tank?
Fluval doesn't publish invertebrate or plant-specific warnings for this product. If you're not sure, dose conservatively and keep an eye on your usual water parameters after adding it.
How does the 2 L bottle differ from the 120 mL and 250 mL sizes?
Same formulation – the 2 L size uses a pump dispenser rather than a pour cap, aimed at larger systems or fish rooms dosing several tanks weekly.
