<\/p>\n If you\u2019ve been in the aquarium hobby for a while, you\u2019ll probably have heard of UV sterilizers. By passing water through UV light, the sterilizer reduces the number of algae and bacteria suspended in the water column.<\/p>\n But while many people claim that UV sterilizers are useful for clearing up cloudy or green water, there are other ways to do that, too. So do you really need this optional aquarium accessory? Here, you\u2019ll find out.<\/p>\n A UV sterilizer is an optional piece of aquarium equipment used to reduce the presence of algae, bacteria, and other pathogens within the water column.<\/p>\n The unit works by running the tank\u2019s water past a germicidal fluorescent UV lamp that damages the DNA of the microorganisms<\/a> within the water column, thereby preventing them from reproducing and reducing their numbers within days.<\/p>\n UV sterilizers are usually either standalone units that use a motor to pump water through a sealed chamber or are passive units without a motor that rely on a canister filter to pump water through them.<\/p>\n Very occasionally, canister filters and hang-on-back filters come with UV sterilizers already installed.<\/p>\n Most aquarium owners don\u2019t use UV sterilizers as they are strictly an optional accessory. Those who do choose to keep one typically only turn it on for short periods to treat green or cloudy water, and to help contain bacterial or even parasitic and fungal infections.<\/p>\n UV sterilizers are especially useful in clearing water of algal blooms that turn the water green, or bacteria blooms that make the water cloudy. When effective, UV treatment may even clear the water within a few days.<\/p>\n Some aquarists also believe that, when used at the right time, UV sterilizers can help to contain outbreaks of parasitic infections like ich and help to reduce the chances of bacterial infections on vulnerable specimens.<\/p>\n While a UV bulb won\u2019t cure fish infections without additional treatments such as medication, it may help to reduce the pathogens from reproducing, as well as reduce the risks of further outbreaks.<\/p>\n Because of this, some aquarists choose to turn their UV units on when their fish are particularly stressed or injured and therefore more susceptible to infection.<\/p>\n It must be understood that UV sterilizers can only treat microbes that are already suspended within the water column<\/em><\/strong>. Organisms that already are floating on the surface or adhered to rocks, glass, plants, gravel, or your aquatic pets won\u2019t run through the unit and are therefore left untreated.<\/p>\n So, while UV can be very effective for treating algae and cyanobacteria suspended in the water, it won\u2019t be much help for treating algae outbreaks on your substrate, glass, and aquarium d\u00e9cor. Similarly, it will only treat parasites in the phase where their offspring are suspended in the water.<\/p>\n Additionally, UV sterilizers are unlikely to help if your water has been stained yellow or brown. Such coloration is usually caused by tannins that are released by materials such as driftwood, peat, or dead leaves.<\/p>\n In some cases, tannins are beneficial, but they can also be\u00a0removed with a carbon filter<\/a> if you prefer to get rid of them.<\/p>\n The one instance where UV sterilizers could prove truly detrimental is when a new aquarium is being cycled.<\/p>\n During cycling, beneficial nitrifying bacteria are busy reproducing and spreading themselves around the aquarium. Not only do they take up residency in your filter, but they also proliferate in the tank\u2019s gravel, and even among rocks and plants.<\/p>\n Since the UV light will sterilize any nitrifying bacteria that are suspended in the water and passing through it, it should always be switched off until the bacterial colonies are firmly established and the tank is fully cycled.<\/p>\n As we\u2019ve already discussed, UV sterilizers either come as stand-alone units or are attached to an existing canister filter. Here we take a closer look at popular models of each kind that have been receiving the most positive reviews from customers.<\/p>\n \t\t<\/p>\n \t\t<\/p>\n \t\t<\/p><\/div>\n<\/div>\n<\/div>\n If you want to try a UV sterilizer without breaking the bank, this handy little standalone unit offers a great solution. While much cheaper than models from big brands, customers of the COODIA \u2018Green Water Killer\u2019 report equally high satisfaction rates.<\/p>\n The unit runs on just 5 watts of electricity, meaning it\u2019ll add very little to your electricity bill. Handy features like an optional air intake\/bubbler and LED light to indicate when the UV bulb needs replacing shows thoughtful design, too.<\/p>\n Suitable for saltwater and freshwater tanks, many customers confirm that it can clear up green water in 3-7 days. While the manufacturers claim it can handle tanks of up to 75 gallons (more than many of its competitors), some users with larger tanks have reported it less effective.<\/p>\n \t\t<\/p>\n \t\t<\/p>\n \t\t<\/p><\/div>\n<\/div>\n<\/div>\n An efficient passive UV sterilizer from a trusted brand, the Fluval In-Line Clarifier has been designed to attach to canister filters with 5\/8\u201d (16 mm) hosing.<\/p>\n As you\u2019d expect from Fluval, the model features innovative technology such as CCFL (Cold Cathode Fluorescent Light) technology that runs cooler than traditional UVC bulbs and lasts up to 30,000 hours (3X longer).<\/p>\n Most customers report high levels of satisfaction with performance and the 2-year warranty offers reassurance that the unit has been made to last.<\/p>\n Important: Please check your canister filter\u2019s hosing diameter is compatible before purchasing, as some models such as the Fluval FX series feature incompatible hosing!<\/em><\/p>\n The most common reason for people installing a UV filter is to clear up green or cloudy water, but for that job, other alternatives can be equally effective and sometimes even longer lasting.<\/p>\n Green or cloudy water in aquaria usually indicates poor water quality that has become too high in nutrients.<\/p>\n When uneaten fish food, dead leaves, algae, and fish waste break down, nitrates and phosphates are released into the water which causes algae and bacteria to bloom. While UV sterilization might help to reduce the symptoms, it\u2019s much better to tackle the root cause of the problem.<\/p>\n Here\u2019s our quick list of tank maintenance basics for keeping water quality and water clarity consistently high:<\/p>\n Because uneaten fish food and excessive fish waste are such major causes of poor-quality water that becomes cloudy, it\u2019s imperative to avoid overfeeding. Indeed, overfeeding is one of the leading causes of poor water quality and fish health issues, especially for beginners.<\/p>\n To overcome this unnecessary issue, never feed more than your fish can eat within 2 minutes. Clean up any leftover food before it begins to break down and foul your water.<\/p>\n You may have noticed that many aquarium filters<\/a> on the market feature carbon filtration, but not all aquarists are well-versed in what that means.<\/p>\n Typically, carbon filtration refers to a filter compartment that houses small pieces of activated carbon, also known as activated charcoal. As water passes through the carbon, its sponge-like structure effectively draws out very small impurities that other types of filter media miss.<\/p>\n By reducing small particles, tannins, and certain dissolved nutrients in the water such as phosphates, carbon filters remove the food that problematic algae and bacteria thrive on, effectively reducing their numbers within days.<\/p>\n While results may not be as fast or dramatic as UV sterilization, when combined with good tank maintenance, carbon filters will usually help your water to remain crystal clear in the long run.<\/p>\n If you do decide to install a carbon filter, just be warned that some of the nutrients it filters out are also necessary for plant growth. Phosphates, in particular, are very important for healthy plant growth, meaning that some planted aquarium<\/a> enthusiasts avoid carbon filtration altogether.<\/p>\n Additionally, carbon will also filter out many types of fish medication as well as tannins from the water. So, if you are attempting to medicate your fish or aiming to create amber-colored, tannin-filled water, carbon filtration isn\u2019t an option.<\/p>\n After weighing up the pros and cons of UV sterilizers, what\u2019s the verdict? We conclude that most aquarium owners don\u2019t need a UV sterilizer, but some might find one useful.<\/p>\nWhat Is a UV Sterilizer?<\/h2>\n
![\"Aquarium](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/04\/Aquarium-with-UV-Sterilizer.jpeg\" "\\"Should")
<\/a><\/figure>\nWhen Are UV Sterilizers Used?<\/h2>\n
For Treating Green or Cloudy Water<\/h3>\n
For Treating Infectious Diseases<\/h3>\n
When UV Sterilizers Won\u2019t Help<\/h2>\n
When UV Sterilizes Should Never Be Used: Cycling a New Aquarium<\/h2>\n
![\"Aquarium](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/03\/Aquarium-filter-output-of-a-tropical-freshwater-aquarium-1.jpeg\" "\\"Should")
<\/a><\/figure>\nThe Pros of Using UV Sterilizers<\/h2>\n
\n
The Cons of UV Treatment in Fish Tanks<\/h2>\n
\n
Featured Products<\/h2>\n
COODIA Internal Green Water Killer Aquarium Filter Tank U-V Pump<\/h3>\n
\n\t\t\t\t![\"COODIA](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/05\/31qlq0mQCvL._SL500_.webp\" "\\"Should")
\n\t\t\t<\/a>\n\t\t<\/div>\nWhat we like:<\/h4>\n
\n
What we don\u2019t like:<\/h4>\n
\n
F<\/strong>luval In-Line UV-C Clarifier<\/h3>\n
\n\t\t\t\t![\"Fluval](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/05\/51TEybJ3JnL._SL500_.webp\" "\\"Should")
\n\t\t\t<\/a>\n\t\t<\/div>\nWhat we like:<\/h4>\n
\n
What we don\u2019t like:<\/h4>\n
\n
Alternatives to UV Treatment<\/h2>\n
Better Tank Maintenance<\/h3>\n
![\"Pumping](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/04\/Pumping-water-out-of-the-aquarium.jpeg\" "\\"Should")
<\/a><\/figure>\nReduce Feeding<\/h3>\n
Carbon Filtration<\/h3>\n
![\"Granules](\"https:\/\/www.aquariadise.com\/wp-content\/uploads\/2024\/04\/Granules-of-filter-carbon-for-aquarium.jpeg\" "\\"Should")
<\/a><\/figure>\nThe Downsides of Carbon Filtration<\/h4>\n
Conclusion \u2013 Do You Need a UV Sterilizer?<\/h2>\n