Cycle Biological Enhancer, 8.4 fl oz (250 mL)

SKU: A8349 | UPC: 015561183499
Format: 8.4 fl oz (250 mL)
Categories: , , ,

Fluval Biological Enhancer goes to work fast, releasing massive amounts of beneficial bacteria that eliminate toxic ammonia and nitrite to establish a biologically-balanced aquarium.

  • All-natural water care – creates a safe biological habitat to prevent fish loss
  • Infused with a powerful team of beneficial bacteria that immediately inoculates aquarium water
  • Extremely effective when setting up a new aquarium or introducing new fish to an existing one
  • Equally useful during water changes and filter media changes, when good bacteria is depleted
  • Regular application helps to completely exclude establishment of undesirable bacteria
  • Eliminates ammonia and nitrite
  • Bio-Floc technology ensures product stability and efficacy, devoid of any contaminants
  • For use in freshwater and saltwater aquariums
Dosage new aquariums:
DAY 1: 25 mL per 10 US Gal (37.8 L)
DAY 2: 10 mL per 37.8 L (10 US Gal)
DAY 3: 10 mL per 37.8 L (10 US Gal)
Dosage after adding fish and or medicating : 10 mL per 37.8 L (10 US Gal)
Weekly dosage for regular maintenance activities and to maintain a strong beneficial biological colony: 5 mL per 37.8 L (10 US Gal)
250 mL (8.4 fl oz) bottle treats up to 1892 L (500 US Gal )
PLANT CARE2019-03-25T05:23:29-04:00



I’m new to aquatic plants. What general maintenance advice can you offer me?

Other than CO2, what other products do you offer to help grow aquatic plants?

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CYCLE BIOLOGICAL ENHANCER2019-03-25T05:26:26-04:00



I would like to cycle a new fishless aquarium by using decomposing food or ammonia. Can I use Cycle Biological Enhancer with this option?

Yes, however, we don’t recommend either method. Ammonium chloride dosing usually results in excess ammonia concentrations, which prolongs the cycle and adds unnecessary pollution. If you already have a healthy aquarium, transfer some established filter media and dose with Fluval Cycle Biological Enhancer.

Why should I dose my tank with Cycle Biological Enhancer regularly?

It helps to maintain a safe, biologically-stable environment by adding in beneficial nitrifying bacteria. Without regular supplementation of this product, less desirable bacteria can dominate your tank and increase the risk for ammonia and nitrite spikes as well as disease. Use weekly for optimal conditions, and especially during water changes and filter media changes.

How do the nitrifying bacteria in Cycle Biological Enhancer survive in a sealed container?

This bacteria has been conditioned to enter a dormancy phase prior to bottling that allows it to survive with minimal food and oxygen intake. It is activated very quickly after introduction to your aquarium.

What are those small beige particles that float around my aquarium after applying Cycle Biological Enhancer?

These particles are called Bio Flocs, which help provide a safe environment for your fish. As per the product instructions, shake the bottle well before each use to include Bio Flocs with each dose.

I’ve been cycling my aquarium for several weeks and have a high level of nitrite. How can I eliminate it ?

We recommend a double dose of Fluval Cycle Biological Enhancer after having performed 50% water changes. At this stage, one or two 50% water changes should dilute the nitrite sufficiently to ensure the bacteria introduced keeps the nitrite level down.

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