- Your cart is empty
- Continue Shopping
Choosing the Right Size UV Sterilizer for Aquarium (Sizing UV Sterilizer)
The chart below provides guidelines for determining the bulb size and flow rate you require for UV sterilization. To use this chart, identify the maximum gph rating in either column that most closely matches the number of gallons in your aquarium. The maximum flow rate should be greater than the number of gallons in the system (tank & sump).
For example, if you have a 100 gallon tank and want to control parasites, you would need a minimum 18 W UV with a maximum flow rate of 100 gph. A 25 W UV at a flow rate of 150 gph would be preferable. With UV sterilizers, bigger is better.
| UV Bulb (Watts) | Maximum Flow Rate for Controlling: | Aquarium Size | |
| Bacteria and Algae | Parasites | ||
| 8 | 120 gph | N/A | under 75 gallons |
| 15 | 230 gph | 75 gph | 75 gallons |
| 18 | 300 gph | 100 gph | 100 gallons |
| 25 | 475 gph | 150 gph | 150 gallons |
| 30 | 525 gph | 175 gph | 175 gallons |
| 40 | 940 gph | 300 gph | 300 gallons |
| 65 | 1700 gph | 570 gph | 570 gallons |
| 80 | 1885 gph | 625 gph | 625 gallons |
| 120 | 3200 gph | 900 gph | 900 gallons |
| 130 | 3400 gph | 1140 gph | 1140 gallons |
Operating Guidelines
While UV sterilizers usually do no harm, do not use one when you first cycle your aquarium, as it may kill beneficial bacteria before they attach to the bio-media or gravel. Also, many medications can be “denatured” by the UV light, so the sterilizer should be turned off when using medications, especially chelated copper treatments. The UV light will “break” the bond of the chelating agent, and the aquarium will have a sudden, lethal concentration of ionic copper.
Once you introduce a UV Sterilizer into your system, carefully monitor your aquarium’s temperature. Depending on your aquarium size and flow rate, a UV Sterilizer may add heat to your aquarium water. If this occurs, you may wish to consider installing a chiller.
Maintenance Requirements
As with all sophisticated pieces of equipment, your UV Sterilizer needs to be properly maintained to remain effective. Quartz sleeves should be cleaned at least every six months. UV bulbs will need to be replaced after 9 to 12 months of continuous use.
UV sterilizers have many advantages and very few drawbacks. In addition to being easy to install, requiring low maintenance, and being affordable, they can provide huge health benefits for your fish. Make sure you get one that is the correct size, operate it under the appropriate conditions, and follow the manufacturer’s maintenance guidelines to ensure that your UV sterilizer can do the job it was designed for.