---
product_id: 707365901
title: "Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349"
brand: "fluval"
price: "R407"
currency: ZAR
in_stock: true
url: https://www.desertcart.co.za/products/707365901-cycle-biological-enhancer-aquarium-water-treatment-8-4-oz-a8349
store_origin: ZA
region: South Africa
---

# Safe, all-natural water care Prevents fish loss by eliminating toxins Powerful beneficial bacteria boost Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349

**Brand:** fluval
**Price:** R407
**Availability:** ✅ In Stock

## Summary

> 🐟 Transform your tank into a thriving aquatic paradise!

## Quick Answers

- **What is this?** Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349 by fluval
- **How much does it cost?** R407 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/707365901-cycle-biological-enhancer-aquarium-water-treatment-8-4-oz-a8349)

## Best For

- fluval enthusiasts

## Why This Product

- Trusted fluval brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Toxin-Free Habitat:** Effectively eliminates harmful ammonia and nitrite, creating a safe environment your fish will thrive in.
- • **Long-Term Water Health:** Regular use prevents harmful bacteria growth, ensuring a consistently healthy aquatic habitat.
- • **Stress-Free Transitions:** Perfect for new setups, fish introductions, and water or filter changes to maintain stable water quality.
- • **Instant Biological Boost:** Infused with a potent blend of beneficial bacteria that jumpstarts your aquarium’s ecosystem from day one.
- • **Versatile for All Aquariums:** 8.4 oz bottle designed for both freshwater and saltwater tanks, making it a must-have for any fish enthusiast.

## Overview

Cycle Biological Enhancer is an 8.4-ounce aquarium water treatment that uses a powerful blend of beneficial bacteria to eliminate ammonia and nitrite, ensuring a safe and healthy environment for freshwater and saltwater fish. Ideal for new tanks, fish introductions, and routine maintenance, it supports stable water quality and prevents harmful bacteria growth.

## Description

Fluval Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349

## Features

- All-natural water care creates a safe biological habitat to prevent fish loss by eliminating ammonia and nitrite
- 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 and useful during water changes and filter media changes, when good bacteria is depleted
- Regular application helps to completely exclude establishment of undesirable bacteria
- 8.4-ounce bottle for use in freshwater and saltwater aquariums

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Fluval |
| Customer Reviews | 4.7 out of 5 stars 2,513 Reviews |
| Item Form | Liquid |
| Item Weight | 8.45 Ounces |
| Liquid Volume | 8.4 Fluid Ounces |
| Manufacturer | Rolf C. Hagen (USA) Corp. |
| UPC | 015561183499 |

## Product Details

- **Brand:** Fluval
- **Liquid Volume:** 8.4 Fluid Ounces
- **Item Weight:** 8.45 Ounces
- **Item Form:** Liquid
- **Manufacturer:** Rolf C. Hagen (USA) Corp.

## Images

![Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349 - Image 1](https://m.media-amazon.com/images/I/71CbLgtkAbL.jpg)

## Available Options

This product comes in different **Size, Style** options.

## Questions & Answers

**Q: How much do I need for setting up a new 75g freshwater tank?**
A: After tank is set up, keep everything running except for lights and if you are running a saltwater tank keep the protein skimmer off. Pour in half of 16.9 oz. bottle upon set up, On the 8th day ,pour the rest in. In my experience on day 14 your tank is cycled, however testing tank water , 1 time I had to wait 16 days. It is recommended to dose the tank when new arrivals are added, I did this for 1week then stopped, I have used this item for 15 years when the original was sold under the CYCLE name which came in 8oz. and 16 oz. Works every time.

**Q: What size bottle is recommended for a 6 gallon tank?**
A: The 8.4 oz seems like a better deal overall compare to the 1oz and 4 oz.  its a little cheaper. However, you would need this every time you do a water change. Some people don't add more when then do a water change, but when you take out water from your tank, your taking out some of the bacteria, thats why its necessary to replace the bacteria. This is by far one of my favorite nitrifying bacteria. This is good to cycle a tank. Plus this bacteria is something you cannot overdose. So for a six gallon tank you can add three to 4 full caps to get a good amount of bacteria in there to start the cycle. Then you can add your first fish. After you add your first fish wait for a few weeks before you add more fish. The first initial fish will help feed the bacteria you put in. This way over a few weeks it will create the ecosystem you want. To be honest Allie, some people add two much fish the first time they get an aquarium and its a big mistake. Eventually they may have  a lot of fish loss due to they tank not being a ecosystem. You want to make sure you create the ecosystem first before you add a lot of fishes. Thats why for the size of your tank one fish is ok with the addition of the bacteria will help create the ecosystem. After a few weeks you can add more. Also if you are doing tropical or saltwater fish make sure you have a heater. If your doing goldfish your not required to have a heater. Acclimate your fishes well too. If you have any more questions feel free to contact me.

**Q: What size do I need for a 40 gallon breeder tank?**
A: The directions state 25 ml per 10 gallons on day 1 (100 ml) and then 10 ml per 10 gallons on day 2 and 3 (40 ml per day) so a total of 180 ml for your 40 gallon breader. I do a sustainment treatment every week of 5 ml per 10 gallons (another 20 ml). I think this is a great way to get and keep a large colony of beneficial bacteria. Good luck with the new tank!

**Q: If I put this in a new tank how quickly will it cycle the tank? Will the bacteria stay in the tank or die off after a bit? Is it cycled permanently?**
A: I would recommend API Stress Zyne Plus. My fish kept dying for the first few weeks. It took almost 8 weeks to for the tank to cycle. So get 2 or 3 fist to start and nothing fancy. Keep testing for Amonia levels. Once the tank cycles, it should be at 0. Then you can get fish you want to keep.

## Frequently Bought Together

- Fluval Cycle Biological Enhancer, Aquarium Water Treatment, 8.4 Oz., A8349
- Fluval Waste Control Biological Cleaner, Aquarium Water Treatment, 8.4 Oz., A8355
- Fluval Clarify Bio for Aquarium Water Treatment, 4-Ounce

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.co.za/products/707365901-cycle-biological-enhancer-aquarium-water-treatment-8-4-oz-a8349](https://www.desertcart.co.za/products/707365901-cycle-biological-enhancer-aquarium-water-treatment-8-4-oz-a8349)

---

*Product available on Desertcart South Africa*
*Store origin: ZA*
*Last updated: 2026-02-23*