Using a UV steriliser in your fish tank involves running it consistently to help maintain clear water and a healthier environment for your fish.
Essentially, you should keep an aquarium UV steriliser running constantly for the best results.
Understanding UV Sterilisation
A UV steriliser works by passing tank water through a chamber where it is exposed to ultraviolet light. This light damages the DNA of free-floating microorganisms like algae spores, bacteria, and parasites, preventing them from reproducing and effectively sterilising the water passing through. This helps to reduce cloudy water and the spread of certain diseases.
The UV unit is typically installed in-line with your filter system, ensuring that water circulates through it.
When and How to Run Your UV Steriliser
According to guidelines for optimal use:
- An aquarium UV steriliser should be switched on and running for 24 hours per day, every day.
Consistent operation is key to controlling the population of harmful free-floating organisms in the water column.
Exceptions to Running 24/7
While continuous operation is the norm, there are specific situations where you should turn off your UV steriliser:
- Tank Setup (Before Fish): When initially setting up a new tank and cycling it, especially before any fish are introduced, you can keep the UV off.
- Adding Beneficial Bacteria: UV light kills bacteria. If you are adding beneficial bacteria products to your tank to help establish or boost the biological filter, turn off the UV steriliser for the duration recommended by the bacteria product manufacturer (usually 24-48 hours) to allow the bacteria to colonise surfaces within the tank and filter.
- Using Medication: If you are treating your tank with medication, check the medication's instructions. Many medications can be broken down or altered by UV light, rendering them ineffective or potentially harmful. Turn off the UV steriliser for the entire duration of the treatment as specified by the medication instructions.
Here's a simple table summarizing when to run your UV:
| Situation | UV Steriliser Status | Notes |
|---|---|---|
| Normal Operation (Fish Present) | ON (24/7) | Maintains water clarity & controls pathogens |
| Tank Setup (No Fish Yet) | OFF | Not necessary until fish are added |
| Adding Beneficial Bacteria | OFF (Temporarily) | UV kills bacteria needed for filter |
| Using Medication | OFF (During Treatment) | UV can degrade many medications |
Placement and Maintenance
- Placement: Install the UV unit according to the manufacturer's instructions, typically after your main biological and mechanical filtration. This ensures water is relatively clean before entering the UV chamber, preventing the sleeve from getting dirty too quickly.
- Flow Rate: Ensure the water flow rate matches the UV steriliser's specifications. Too fast, and organisms aren't exposed long enough; too slow, and the water isn't treated efficiently.
- Maintenance: Regularly clean the quartz sleeve around the UV bulb and replace the UV bulb periodically (usually every 6-12 months, depending on the manufacturer) as its effectiveness decreases over time, even if it still glows.
By following these guidelines, you can effectively use a UV steriliser to contribute to a healthier and clearer aquarium environment.
