Activated carbon filters are not effective at removing fluoride from water. While activated carbon is great at removing many impurities, including chlorine, volatile organic compounds, and some heavy metals, it is not effective at removing fluoride. To effectively remove fluoride from water, a specialized filter such as a reverse osmosis system or a distillation unit is needed. **

Generally, an external filter is quieter than an internal filter. This is because external filters are usually placed outside the aquarium, reducing the noise level inside the tank. Internal filters, on the other hand, are submerged in the water, which can create more noise as the water flows through the filter. Additionally, external filters often have larger compartments for filter media, allowing for better noise reduction compared to internal filters. **

Yes, the Mann-Filter oil filter is genuine. Mann-Filter is a reputable brand known for producing high-quality filters that meet or exceed OEM specifications. It is important to purchase genuine filters to ensure proper filtration and protection for your vehicle's engine. **

Blue light filter is used to reduce the amount of blue light emitted by screens, such as those on computers, smartphones, and tablets. Blue light can disrupt our sleep patterns by suppressing the production of melatonin, the hormone that regulates sleep. By using a blue light filter, especially in the evening, we can reduce the negative impact of blue light on our sleep quality and overall health. **

When choosing an external filter for your aquarium, it is important to consider the size of your tank, the type of fish you have, and the level of filtration required. Popular options include canister filters, hang-on-back filters, and sump filters. Canister filters are known for their high filtration capacity and are ideal for larger tanks, while hang-on-back filters are easy to install and maintain. Sump filters are often used in larger setups and provide excellent biological filtration. Ultimately, the best external filter for your aquarium will depend on your specific needs and preferences. **

I'm sorry, but your question is not clear. Can you please provide more context or clarify what you mean by "filter 2"? Thank you. **

A shooting club can exist without its own firearm by allowing members to bring their own firearms to use during club activities. The club can also partner with local shooting ranges or firearm retailers to provide access to firearms for club members. Additionally, the club can organize group firearm rentals for its members to use during events and competitions. By utilizing these methods, a shooting club can still provide a space for members to practice and compete in shooting sports without needing to own its own firearms. **

An open air filter, also known as a sports air filter, is a type of air filter that is designed to allow more air flow into the engine compared to a standard air filter. This increased air flow can potentially improve engine performance by providing more oxygen for combustion, resulting in increased horsepower and torque. Open air filters are often used in high-performance vehicles or in racing applications where maximizing engine performance is a priority. **