Water filter units can be found in most hardware stores and from professional suppliers
. These units vary in type, size, operation, and cost. Depending on the contaminants you are trying to remove, the type of system you will need varies. When trying to decide the system you need, the first step in determining the best system is to have a water analysis done by a professional. Once you know the contaminants you are dealing with next look at your application. Some water filter units are designed to continuously filter all the water for the household while other models are designed to filter at only one tap. Depending on your needs, you will also need to consider the mounting requirements and maintenance requirements. If you choose the whole house model, you will be filtering water for washing clothes, showers and all other aspects using water. This system will depend on the water source as well. This will also require easy access for servicing and filter changes. Also keep in mind the chance of spilling the contaminated water and filter when changing so make sure its not on a wood floor. Other water filter units are designed for easily attaching directly to faucets. These are found in kitchens and bathrooms. These units only filter the water for use at the faucet and no other area in the house. These types of units are cartridge based. These types of units are easy to service however their service life on the cartridge is relatively short.