LD Series Lights 123Wx55Hmm: Simple to install and use. Operates on a low-voltage DC 12V power supply, ensuring safety and dependability. Bright LED illumination with high luminous efficiency, promoting energy conservation, durability, and eco-friendliness. Includes a wireless remote control for effortless operation. Adjustable LED colors to suit your preferences. Brightness settings can be modified at multiple levels. Ideal for general lighting and perfect for aquariums. Offers strong light penetration into water with low heat emission. * Perfect for indoor settings or various occasions. The light features an innovative design, stylish look, and is easy to maintain. LD-20A: 6W, 524L x 123W x 55Hmm LD-24A: 7W, 624L x 123W x 55Hmm LD-36A: 9W, 924L x 123W x 55Hmm LD-48A: 15W, 1242L x 123W x 55Hmm

Suction for temperature regulation, temperature regulation e, temperature regulation+ e

Round Air Stone Disperse air throughout your aquarium and ensure your fish have the oxygen they need to thrive. An essential item for every aquarium setup. These stones are built to last and are highly durable. They offer a high rate of dissolved oxygen. Produce consistent, small bubbles instead of a few large ones.

The latest EHEIM powerLED+ is the ideal lighting solution for your aquarium.Covering the entire spectrum from natural sunlight to white and actinic light, our new LED lamps are meticulously designed. Each spectrum is carefully balanced to promote the growth of plants or corals while enhancing the vibrant colors in your aquarium.The LEDs can be customized to suit any aquarium size by adjusting the brackets to the appropriate length, or you can easily swap out existing fluorescent tubes with our LED by using the specially crafted adapter designed for current light units. Experience EHEIM quality – proudly made in Germany.Benefits of the EHEIM powerLED+A premium and energy-efficient alternative to T5 fluorescent tubes (including reflector!)Provides full-depth lighting, even in deeper aquariums.LED strips can be combined to achieve the ideal balance for plant or coral growth.Offers a complete sunlight spectrum with optimal output for photosynthesis (freshwater).Accurately reproduces the natural hues in the aquarium.Average lifespan exceeds 50,000 hours.Constructed with high-quality, robust anodized aluminum housing, resistant to marine water.Available in 8 lengths to fit aquariums ranging from 36 to 135 cm long (lengths can be adjusted by extending the stainless steel support brackets).Compatible with existing fluorescent light tube units (T8, T5); simply replace old tubes using the EHEIM T8-/T5 adapter (see accessories).Single and double wire suspension options available for open aquariums (see accessories).Highly efficient safety power supply (24V) that conserves energy.Multiple lamps can be connected to a single power supply unit using our Y adapter (accessories).Compatible with LEDcontrol.EHEIM powerLED fresh daylightBright daylight (7,000 K) provides a full sunlight spectrum (full spectrum).Natural representation of colors in both fish and plants.Balanced blue and/or red spectrum range that supports robust plant growth.Outstanding energy efficiency (120 lm/W) and brightness.Can also be combined with EHEIM powerLED plants for more demanding plant species.Suitable for aquariums up to approximately: 1250-1406mm.Light color: 6200Rated light flux: 5440Lifetime: 50,000 hoursManufacturer's warranty: 3 Year(s)Performance at 50 Hz: 34.8 WattEnergy Efficiency Class: DSea water: NoFreshwater: Yes

Karis Impeller Karis Impeller Karis Ks-1400C Impeller      Length: 8 cm      Ø       24 mm Karis Ks-2000C Impeller      Length: 8 cm      Ø       30 mm

Generates bubbles in your aquarium when connected to an air pump. An excellent tool to assist aquatic fish with their breathing needs. Ideal for both freshwater and saltwater aquariums, as well as hydroponic systems. Used in sewage treatment facilities for aeration and mixing, helping to prevent the buildup of large sediment particles and removing some organic matter. Enhances oxygen levels in fish ponds (aquaculture environments) to support eutrophic water bodies and biological growth. Boosts oxygen supply for the transportation of live fish and seafood. Acts as a purifier in aquariums, aiding in water purification and filtration, ozone sterilization, and oxygen enhancement. Suitable for other applications requiring air diffusion.

The EHEIM reeflexUV effectively minimizes microorganisms in your aquarium's water while significantly improving clarity like never before.This innovative product from EHEIM features a built-in reflector that enhances the effectiveness of the UV-C radiation designed to eliminate microorganisms. Unlike traditional UV sterilizers that divert water around the UV-C lamp, the EHEIM reeflexUV allows water to flow directly past the UV-C source, ensuring no loss of efficiency, requiring less energy, and achieving a performance level that is 1.8 times greater. The EHEIM reeflexUV is meant to be used alongside a filter to target small organisms such as microorganisms and algae spores within your aquarium. It is available in five different models suitable for aquariums ranging from 80 to 2000 liters.For aquariums of approximately:80 LitersFor aquariums with a maximum capacity of:350 LitersHeight:350 mmWidth:115 mmDepth:130 mmPower at 60 Hz minimum:7 WattMaximum pressure at 50 Hz:0.8 barFrequency:50 HzManufacturer warranty:3 Year(s)Freshwater compatible:YesSaltwater compatible:YesAdvantages of the EHEIM reeflexUVSwiftly and effectively reduces harmful bacteria and fish parasites during their infectious stages in the water.reeflexUV 350 = Maximum flow rate: 200 l/hreeflexUV 500 = Maximum flow rate: 400 l/hreeflexUV 800 = Maximum flow rate: 600 l/hreeflexUV 1500 = Maximum flow rate: 1000 l/hreeflexUV 2000 = Maximum flow rate: 1500 l/hRemoves cloudiness caused by algae or bacteria.reeflexUV 350 = Maximum flow rate: 400 l/hreeflexUV 500 = Maximum flow rate: 800 l/hreeflexUV 800 = Maximum flow rate: 1200 l/hreeflexUV 1500 = Maximum flow rate: 2000 l/hreeflexUV 2000 = Maximum flow rate: 3000 l/hThe internal high-gloss aluminum reflects UV-C light for more effective sterilization.Delivers excellent results while consuming minimal energy (1.8 times more efficient than standard UV sterilizers).No loss of performance due to the specialized design that allows water to flow uninterrupted.Perfect for breeding tanks as it minimizes infection risks.Beneficial bacteria are securely retained in the filter since only floating organisms are affected.AUTO-OFF: automatic safety shut-off feature when changing the lamp.Simple to install with the included mounting bracket.Flexible installation options, with no specific positioning or flow direction required.Included accessories: EHEIM UV-C lamp, mounting unit, ballast with power cord, 2x hose connectors ø 12/16 mm, 2x hose connectors ø 16/22 mm.Advanced technology for pristine water and vibrant fish.In a UV sterilizer, aquarium water is processed as a thin layer around a UV-C lamp (burner). The UV-C light penetrates the water, effectively eradicating microorganisms, algae spores, and other tiny organisms.Unlike conventional systems that irradiate water from only one side, EHEIM's design incorporates a reflector that allows the UV light to penetrate the water from multiple angles, resulting in significantly superior performance.Moreover, the EHEIM reeflexUV features a straightforward water flow design. Water flows directly around the burner without unnecessary diversions, ensuring optimal performance.The AUTO OFF feature guarantees safety. As UV-C radiation can harm skin and eyes, the reeflexUV will immediately shut down when the device is opened.Additional information:Due to the limited volume of water, aquariums typically have a higher bacterial count compared to normal water sources. Reducing this count to a more typical level is beneficial, but it’s important to note that aquarium water should never be entirely free of bacteria.The UV sterilizer targets only the floating bacteria in the water. Established cleaning bacteria in the filter (as seen in biological filtration) and those in the substrate are preserved.Cloudiness in the water, caused by bacteria or suspended algae, is effectively eliminated through UV sterilization. Algal growth is curtailed since the spores are destroyed.UV sterilizers foster healthier fish by reducing the likelihood of infection. They are especially recommended for breeding tanks, as harmful pathogens can adhere to eggs or infect young fish that are still developing their immune systems.UV sterilization does not alter water parameters.The light source in this product is solely intended for disinfecting aquarium water.

Clear gray aquarium tubing.• Versatile aquarium tubing suitable for water changes, filters, and more.• Gray tinted, see-through tubing that is free of heavy metals.• Offered in both air and water tubing options in different diameters.hose Ø16/22 mm (3 m)

The EHEIM reeflexUV effectively reduces microorganisms in your aquarium water and tackles turbidity with unprecedented efficiency.As a hallmark innovation from EHEIM, the reeflexUV features a built-in reflector that significantly amplifies the microorganism-neutralizing UV-C radiation. Unlike traditional UV sterilizers, where water navigates convoluted paths around the UV-C bulb, the EHEIM reeflexUV allows water to flow directly past the source. This ensures no performance loss and consumes less energy, achieving effectiveness that is 1.8 times greater. It's essential to pair the EHEIM reeflexUV with a filter to effectively diminish small organisms such as microorganisms and algae spores in your aquarium. Available in five models, it caters to aquariums ranging from 80 to 2000 liters.For aquariums around:400 LitersFor aquariums up to approximately:800 LitersHeight:500 mmWidth:115 mmDepth:130 mmPower at 60 Hz min:11 WattMaximum pressure at 50 Hz:0.8 barFrequency:50 HzManufacturer warranty:3 Year(s)Freshwater:YesSaltwater:YesAdvantages of the EHEIM reeflexUVEfficiently and quickly reduces harmful bacteria and fish parasites during their infectious stages in the water.reeflexUV 350 = Maximum flow rate: 200 l/hreeflexUV 500 = Maximum flow rate: 400 l/hreeflexUV 800 = Maximum flow rate: 600 l/hreeflexUV 1500 = Maximum flow rate: 1000 l/hreeflexUV 2000 = Maximum flow rate: 1500 l/hEffectively eliminates turbidity caused by algae or bacteria.reeflexUV 350 = Maximum flow rate: 400 l/hreeflexUV 500 = Maximum flow rate: 800 l/hreeflexUV 800 = Maximum flow rate: 1200 l/hreeflexUV 1500 = Maximum flow rate: 2000 l/hreeflexUV 2000 = Maximum flow rate: 3000 l/hThe high-gloss aluminum interior reflects the UV-C light, enhancing the sterilization process.Outstanding performance with low energy usage (1.8 times more effective than traditional UV sterilizers).No reduction in performance, as the specialized design prevents water redirection.Also perfect for breeding tanks, minimizing the risk of infection.Beneficial bacteria are safely preserved in the filter, as only suspended organisms are captured.AUTO-OFF: automatic safety shut-off when changing the lamp.Simple installation with the included mounting bracket.Flexible installation options, with no set installation position or flow direction.Included accessories: EHEIM UV-C lamp, mounting unit, ballast with power cable, 2 hose connection taps ø 12/16 mm, 2 hose connection taps ø 16/22 mm.Advanced technology for clear water and healthy fish.In a UV sterilizer, aquarium water flows as a thin film past a UV-C lamp (bulb). The UV-C radiation penetrates the water, effectively eliminating microorganisms, algae spores, and other tiny organisms.In contrast to standard technology, which irradiates water from one side only, EHEIM incorporates a reflector that allows the reflected radiation to penetrate the water from multiple angles. This design achieves a significantly higher performance level.Additionally, the EHEIM reeflexUV avoids a complicated water flow system, allowing water to flow directly around the bulb without detours, ensuring no performance is lost.The AUTO OFF feature provides optimal safety. Since UV-C radiation can harm skin and eyes, the reeflexUV automatically turns off when the device is opened.Important information:Due to the limited volume of water, the bacterial count in an aquarium tends to be higher than in typical waters. It's beneficial to lower this count to a normal level, but the aquarium water should never be entirely devoid of bacteria.The UV sterilizer captures only floating bacteria in the water. Cleaning bacteria residing in the filter (as part of biological filtration) and the substrate are unaffected.UV sterilization effectively removes turbidity caused by bacteria or floating algae. It also suppresses algae growth by killing their spores.Generally, UV sterilizers promote healthier fish by reducing the risk of infections. They are particularly recommended for breeding tanks, as dangerous pathogens can settle on eggs or infect young fish that have not yet developed sufficient resistance.UV sterilization does not alter the water's parameters.The light source in this product is designed solely for disinfecting aquarium water.

Replacement Impeller for Quick Vac

LD Series Lights 123Wx55Hmm Simple to set up and operate. Powered by a safe and dependable DC 12V low-voltage supply. Featuring high brightness LED lights that offer excellent luminous efficiency, energy savings, durability, and environmental friendliness. Comes with a wireless remote control for effortless operation. Adjustable LED colors for various lighting needs. Brightness levels can be customized to suit your preferences. Ideal for general lighting and specifically designed for aquarium use. Provides impressive light penetration in water while maintaining a low-temperature light output. * Perfect for indoor settings or other occasions. The design is innovative, aesthetically pleasing, and easy to maintain. Specifications: LD-20A: 6W, 524L x 123W x 55Hmm LD-24A: 7W, 624L x 123W x 55Hmm LD-36A: 9W, 924L x 123W x 55Hmm LD-48A: 15W, 1242L x 123W x 55Hmm

Mesh bag (2 l)

Algae cleaning brush for rapidCleanerThis algae brush is designed for aquariums and is compatible with the EHEIM rapidCleanerIdeal for the effective removal of thread algae and maintaining clean aquariumsSaltwater: YesFreshwater: YesPacking dimensions (Width): 12.1 cmPacking dimensions (Height): 24 cmPacking dimensions (Depth): 3 cm

Universal ceramic impeller shaft and bushing compatible with models 1200, eXperience (2426), and 1250/2252/2426.

This versatile green hose comes in various sizes (12/16; 16/22; 25/34, and more). It's perfect for multiple uses in your aquarium, including air supply, water changes, and filtration.

Ceramic impeller shaft and bushings designed for classic 350/600 models

1. Measure out 3 ml of the test solution. 2. Introduce 2 drops of the indicator solution and stir well. 3. Match the resulting color with the provided color chart pH 0.0 -> Red to 10.0 -> Dark Violet 250 Tests

You can utilize the EHEIM climacontrol+ to lower the water temperature on warm days or raise it on cooler days, all according to the needs of your aquarium's inhabitants.The EHEIM climacontrol+ is our latest electronically controlled climate management device. You can effortlessly set the desired water temperature wirelessly using your smartphone, tablet, or PC/MAC. If the water becomes too warm, the unit will automatically cool it down, and if it gets too cold, it will warm it back up. This device takes care of everything for you.Additionally, it alerts you in advance if any issues arise; for instance, if the temperature exceeds or falls below the required level by 2 °C for over 5 minutes, you will receive a warning email.High temperatures outdoors can often lead to an increase in the aquarium water temperature during summer months. This can be extremely detrimental to fish and other aquatic life. For instance, if the temperature gets too high, corals can perish in marine aquariums, while oxygen depletion and rapid algae growth can occur in freshwater tanks.The EHEIM climacontrol+ is the perfect climate management solution for aquariums. It operates with low energy consumption and uses environmentally friendly coolant.There are three models available: S, M, and L, suitable for aquariums of up to 500, 1000, and 2000 liters, respectively, and they all come with a 3-year warranty.Features of the EHEIM climacontrol+Electronically controlled continuous flow climate control system with Wi-Fi capabilitiesTemperature adjustment and monitoring via Wi-Fi using a smartphone, tablet, or PC/MACCooling and heating functions availableConsistent regulation of water temperatureTemperature management for both freshwater and marine aquariumsAccurate temperature detection ranging from 5 °C to 35 °CAutomatically activates when temperatures go above or below a set targetWarning email notification if the temperature fluctuates by 2 °C for more than 5 minutesContinuously displays the current water temperature during operationUsable in ambient temperatures ranging from 10 °C to 38 °CHighly energy-efficient and eco-friendly climate control unit with ozone-friendly refrigerant (R290)Designed to operate exclusively with clean (filtered) water; for marine tanks, it should use water from the filter tank via a separate pump, or for freshwater tanks, it can be installed behind the external filter (alternatively, it can be used with a separate pump and pre-filter taken directly from the aquarium)Available in three models: S, M, and L for aquariums with capacities of up to 500, 1000, and 2000 litersConstructed from high-quality components and materials, backed by a 3-year warrantyImportant for marine aquariums:The ideal temperature for corals is between 24 and 26 °C; temperatures exceeding 29.5 °C can be lethal.Important for freshwater aquariums:The temperature should remain below 30 °C. Going above this level can lead to oxygen deficiency, hindered plant growth, and rapid algae growth.EHEIM climacontrol+ – the electronically controlled climate management device with WLAN functionality and numerous benefitsThe primary function of the EHEIM climacontrol+ is to cool the aquarium water when it becomes excessively warm. It offers both cooling and heating functionalities.During summer, elevated outdoor temperatures can frequently result in overheated aquarium water—especially in small rooms that warm up quickly, attics, or areas exposed to direct sunlight. Even enclosed tanks that trap heat from lighting may experience temperature spikes.The EHEIM climacontrol+ includes WLAN capabilities. The Wi-Fi controller allows you to set the optimal target temperature through your smartphone, tablet, or PC/MAC. Once the temperature goes above or below the set point, the device activates to cool or heat the water until the desired temperature is achieved. The current water temperature is always displayed, and if it deviates by 2 °C for over 5 minutes, a warning email will be sent to you.The EHEIM climacontrol+ is a continuous flow unit that should only be used with clean (filtered) water. For marine aquariums, this means using water from the filter tank with a separate pump. In freshwater setups, it can be positioned behind the external filter. (Alternatively, it can also be operated via a separate pump with a pre-filter directly from the aquarium.)The EHEIM climacontrol+ is designed to be energy-efficient and environmentally conscious. The refrigerant (R290) replaces harmful ozone-depleting substances, ensuring a minimal global warming potential (GWP).When installing the unit, ensure that the ventilation openings remain unobstructed. There should be at least a 50 mm gap from walls and other structures. In the base cabinet of an aquarium setup, appropriate cutouts must be made for fresh air intake and warm exhaust airflow (for more details, refer to the operating instructions).

The EHEIM reeflexUV effectively reduces microorganisms in the aquarium water and enhances clarity like never before.This product showcases EHEIM's innovative spirit: featuring a built-in reflector, the UV-C radiation that eliminates microorganisms is significantly intensified. Unlike traditional UV sterilizers that route water through detours past the UV-C lamp, the EHEIM reeflexUV allows water to flow directly, ensuring maximum efficiency without power loss. You'll find that its effectiveness is 1.8 times greater. It is essential to use EHEIM reeflexUV alongside a filter to minimize small organisms such as microorganisms and algae spores in your aquarium. Available in five models, it accommodates aquariums ranging from 80 to 2000 litres.For aquariums of approximately:700 LitersFor aquariums up to about:1500 LitersDimensions:Height: 500 mmWidth: 115 mmDepth: 130 mmPower at 60 Hz min.:18 WattMaximum pressure at 50 Hz:0.8 barFrequency:50 HzManufacturer warranty:3 Year(s)Freshwater compatible:YesSaltwater compatible:YesAdvantages of the EHEIM reeflexUVQuickly and effectively eliminates harmful bacteria and fish parasites during their infectious stages from the water.reeflexUV 350 = Maximum flow capacity: 200 l/hreeflexUV 500 = Maximum flow capacity: 400 l/hreeflexUV 800 = Maximum flow capacity: 600 l/hreeflexUV 1500 = Maximum flow capacity: 1000 l/hreeflexUV 2000 = Maximum flow capacity: 1500 l/hRemoves cloudiness caused by algae or bacteria.reeflexUV 350 = Maximum flow capacity: 400 l/hreeflexUV 500 = Maximum flow capacity: 800 l/hreeflexUV 800 = Maximum flow capacity: 1200 l/hreeflexUV 1500 = Maximum flow capacity: 2000 l/hreeflexUV 2000 = Maximum flow capacity: 3000 l/hThe high-gloss aluminum interior reflects UV-C light, ensuring more effective sterilization.Achieve outstanding results while consuming less energy (1.8 times more effective than standard UV sterilizers).No performance degradation occurs as the water flows directly around the burner without redirection.Perfect for breeding tanks, as it lowers the risk of infection.Beneficial bacteria are safely kept in the filter as it captures only floating organisms.AUTO-OFF feature: automatic safety shutdown when the lamp is changed.Simple installation with the included mounting bracket.Flexible installation options, with no specific installation orientation or flow direction required.Included accessories: EHEIM UV-C lamp, mounting unit, ballast with power cord, 2 hose connection taps ø 12/16 mm, and 2 hose connection taps ø 16/22 mm.Advanced technology for pristine water and healthy fish.In a UV sterilizer, aquarium water is passed as a thin film past a UV-C lamp (burner). The UV-C radiation penetrates the water, effectively exterminating microorganisms, algae spores, and other tiny organisms.Using traditional technology, water is irradiated only on one side. In contrast, EHEIM incorporates a reflector that allows the reflected radiation to penetrate the water from multiple angles. This approach significantly enhances the performance of the reeflexUV.Moreover, the EHEIM reeflexUV features a straightforward water flow design. The water flows around the burner without redirection, ensuring no performance loss.The AUTO OFF function provides an added layer of safety, as UV-C radiation can harm skin and eyes. The reeflexUV automatically shuts off when the device is opened.Additional information:In comparison to typical waters, the bacterial count in an aquarium is notably higher due to the limited volume of water. It is advantageous to reduce this count to restore it to a normal level. However, aquarium water should never be completely free of bacteria.Only floating bacteria are captured by the UV sterilizer, leaving beneficial cleaning bacteria in the filter (as per biological filtration) and bacteria in the gravel substrate unharmed.Cloudiness in the water, caused by bacteria or free-floating algae, is efficiently eliminated through UV sterilization. In essence, algae growth is inhibited since the spores are exterminated.UV sterilizers generally promote healthier fish by reducing the risk of infections. They are especially recommended for breeding tanks, as dangerous pathogens can attach to eggs or infect young fish that lack sufficient resistance.UV sterilization does not alter the water parameters.This product's light source is intended solely for disinfecting aquarium water.

EHEIM reeflexUV effectively diminishes microorganisms in the water and removes cloudiness more efficiently than ever before.The EHEIM reeflexUV represents yet another groundbreaking innovation from EHEIM: featuring a built-in reflector, the UV-C radiation that targets microorganisms is greatly intensified. Unlike traditional UV sterilizers that divert water around the UV-C bulb, the EHEIM reeflexUV allows water to flow directly past it. This results in no loss of efficiency, lower energy consumption, and an effectiveness level that is 1.8 times higher. The EHEIM reeflexUV is designed to be used alongside a filter to eliminate small organisms such as microorganisms and algae spores in your aquarium. Available in five models, it caters to aquariums ranging from 80 to 2000 liters.For aquariums of about:300 LitersFor aquariums up to approximately:500 LitersHeight:380 mmWidth:115 mmDepth:130 mmPower at 60 Hz min:9 WattMax pressure at 50 Hz:0.8 barFrequency:50 HzManufacturer warranty:3 Year(s)Freshwater:YesSaltwater:YesAdvantages of the EHEIM reeflexUVQuickly and effectively reduces harmful bacteria and fish parasites in their infectious stages in the water.reeflexUV 350 = Maximum flow capacity: 200 l/hreeflexUV 500 = Maximum flow capacity: 400 l/hreeflexUV 800 = Maximum flow capacity: 600 l/hreeflexUV 1500 = Maximum flow capacity: 1000 l/hreeflexUV 2000 = Maximum flow capacity: 1500 l/hEliminates cloudiness caused by algae or bacteria.reeflexUV 350 = Maximum flow capacity: 400 l/hreeflexUV 500 = Maximum flow capacity: 800 l/hreeflexUV 800 = Maximum flow capacity: 1200 l/hreeflexUV 1500 = Maximum flow capacity: 2000 l/hreeflexUV 2000 = Maximum flow capacity: 3000 l/hInternally installed high-gloss aluminum reflects the UV-C light, leading to more effective sterilization.Outstanding results with low energy usage (1.8 times more efficient than traditional UV sterilizers).No loss of performance due to a unique design that allows water to flow directly around the burner.Also perfect for breeding tanks, as it minimizes infection risks.Beneficial bacteria are safely retained in the filter since only suspended organisms are captured.AUTO-OFF: automatic safety shutdown when lamp replacement is necessary.Simple to attach with the included mounting bracket.Flexible installation with no specific installation requirements or flow direction.Accessories: EHEIM UV-C lamp, mounting unit, ballast with power cable, 2x hose connection taps ø 12/16 mm, 2x hose connection taps ø 16/22 mm.Special technology for clean water and healthy fish.In a UV sterilizer, aquarium water passes as a thin film past a UV-C lamp (bulb). The UV-C radiation penetrates the water, effectively killing microorganisms, algae spores, and other small organisms.Using conventional technology, water is irradiated on just one side. In contrast, EHEIM incorporates a reflector that allows the reflected radiation to penetrate the water from multiple angles. This results in a significantly enhanced performance level.Moreover, the EHEIM reeflexUV features a straightforward water flow system. Water flows around the bulb without detours, ensuring no performance loss.The AUTO OFF feature provides an optimal safety level. Since UV-C radiation can harm skin and eyes, the reeflexUV automatically shuts off when the device is opened.What you should also be aware of:In comparison to normal water, the bacterial count in an aquarium is relatively high due to the limited volume of water. Reducing this count to a more standard level is beneficial. However, aquarium water should never be completely devoid of bacteria.Only floating bacteria in the water are captured by the UV sterilizer. Established cleaning bacteria in the filter (as in biological filtration) and bacteria in the gravel substrate remain unharmed.Cloudiness caused by bacteria or floating algae is efficiently removed via UV sterilization. Essentially, algae growth is inhibited as the spores are eradicated.UV sterilizers generally promote healthier fish by lowering the risk of infection. They are particularly recommended for breeding tanks since harmful pathogens can attach to eggs or infect young fish that lack sufficient resistance.UV sterilization does not alter the water's parameters in any way.The light source included in this product is exclusively intended for the disinfection of aquarium water.