The answer depends on what type of water you're using: if it’s municipal tap or well water, one filter should suffice; unless you have special needs such as sediment removal or very hard water (over 10gpg), most standard household filtration systems will do the job. However, if you’re utilizing spring or rainwater sources, then multiple stages may be necessary due to their variable mineral content and potential pathogens. In this case, having dedicated filters for each source is ideal.