If you have studied health for any length of time likely appreciate that drinking pure water is an essential element of staying healthy.  Unfortunately most people believe they can obtain their water requirements from sodas, coffee, highly processed fruit juices, and superficially healthy options like Gatorade.  While drinking these fluids will clearly keep you alive, there is a huge gap in what they will do to your or your family's health. 
Pure Water is Your BEST Choice!
    It is my strong opinion that for the bulk of the population, replacing these junk fluids with pure water is simply one of the most powerful lifestyle changes one can make to start improving their health.   Drinking pure water regularly is so important that I put it at the TOP of my recommended choices to make to get healthy. Fortunately many people are realizing this and they are choosing water over junk fluids. However many are using tap water which is loaded with chlorine, fluoride, drugs flushed down the toilet, arsenic, and even rocket fuel.
The Bottled Water Myth
    Drinking bottled water is a major improvement over junk fluids and tap water.   However, in these challenging economic times, it makes more sense to find a more cost effective and environmentally sustainable option than bottled water.     Here's why...
Up to 40% of bottled water is actually just bottled tap water that may or may not receive additional treatment and filtering.
Bottled water can contain chlorine and fluoride -- chemicals I feel are unhealthy and should not be in your drinking water.
A 4-year study released by the Natural Resources Defense Council (NRDC) found 1/3 of the water bottles tested contained synthetic organic chemicals and bacteria.
The typical plastic used for bottled water is polyethylene terephthalate (PET) -- this material potentially leaches antimony and other toxic chemicals into your water. 
Landfills polluted with discarded plastic bottles further contribute to the deterioration of your environment.
Buying bottled water is expensive -- it's estimated a $1.50 bottle of water costs just $0.22, leaving $1.28 per bottle in profits.
There's a huge strain placed on your environment to produce and distribute bottled water around the world -- an estimated 50 billion plastic bottles are produced each year.
Regulation of bottled water is another concern.
The Environmental Protection Agency (EPA) regulates public water supplies, but has no authority over bottled water.
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    For example, there are not any specific requirements regarding proximity of bottled water sources to industrial facilities or waste dumps. And there's no official procedure in place for shutting down bottled water sources if they become contaminated.  Now you know the reasons why I don't recommend bottled water -- there are just too many potential risks and unknown consequences to your health.  If you're concerned about how to carry your water with you, there are safe alternatives to the typical PET plastic bottles and potentially risky water inside. You clearly want to avoid PVC plastic containers. These are typically milky white and the type that most milk used to come in years ago. They leave a clear and obvious odor to the water because they leach loads of toxic plasticizers in the water.  You can use safe plastics which aren't known to leach harmful substances:
Polypropylene, designated "#5 PP"
High-density polyethylene, designated "#2 HDPE"
Low-density polyethylene, designated "#4 LDPE"
So, what source of clean, refreshing water remains? What about tap water flowing freely from your kitchen faucet?
How water straight from your tap can be harmful to you health!!!
    From your kitchen faucet, you could be filling your glass with the potential hazards of chlorine, fluoride, bacteria, pesticides, disinfection byproducts (DBPs) arsenic, rocket fuel, discarded potent pharmaceutical drugs and much more...  Tap water can be full of all types of hidden contaminants you can't see with the naked eye.   These contaminants not only can affect the taste and odor of home tap water, but they can potentially interrupt the balance of your body's natural functions.  Even if your water looks and tastes fine, bear in mind many contaminants are tasteless, odorless, and colorless.  Some contaminants can be so harmful they're measured in "parts per million" or "parts per billion". Only one drop of one of these harmful toxins in a gallon of water can be extremely harmful to your wellbeing.  Disinfection byproducts are one of the most toxic elements in the water supply and we didn't even know about them until relatively recently.  What concerns me more though is that there are likely other even more harmful elements in tap water that today's technology can simply not inform us of.
Why adding Fluoride to you water is unhealthy
    One of my top issues with tap water and MANY bottled waters is fluoride. Please remember that nearly half of bottled water is filtered tap water and most municipal water supplies are contaminated with fluoride. Additionally some water companies actually add fluoride to their bottled water. If you are still confused about fluoride and believe it is healthy I would strongly encourage you to review the evidence. There is plenty on this site but a quick Google search will be very enlightening
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    The very brief summary is that in an attempt to reduce cavities, many. countries began adding fluoride their municipal drinking water supplies.
They did this because they were convinced that most "experts" were in favor of water fluoridation. However, like many areas related to health, this issue was manipulated by special interest groups to conveniently dispose of industrial byproduct poisons. It didn't take long for some countries to put the pieces together, which is why Sweden, Norway, Denmark, Germany, Italy, Belgium, Austria, France, and the Netherlands ban fluoride from their drinking water.
Here are just some of the concerns with fluoride...
Accumulates in your bones, causing them to be brittle and easily fractured
Inactivates some of your enzyme systems
Disrupts your immune system, causing it to attack normal working tissues in your body
Accelerates your aging process
Causes cellular and genetic damage
Damages  your tooth enamel by hardening the outer surface
Highly toxic chlorine found in water
    Chlorine is a chemical used in municipal water supplies. It was first introduced into U.S. water supplies in 1908 Chlorine has been enormously effective at reducing water borne illnesses such as cholera, typhoid, dysentery, and hepatitis.  What may surprise you is that although chlorine can kill these bacteria its is relatively non-toxic to you and your family.  However most all water supplies have dissolved organic matter in the water that is a result of leaves and twigs that floats into the water.  This is where the problem starts as chlorine interacts with these organic materials to produce disinfection byproducts more commonly referred to as DBPs.  The two primary DBP categories  called trihalomethanes (THMs) and haloacetic acids (HAA5s).
These DBPs have been linked to potential...
Damaging effects to your cardiovascular system
Harmful impacts to your respiratory system
Unhealthy functioning of your renal system
Disruptions to your central nervous system
Weakening of your immune system
These DBPs may be up to 10,000 -100,000 times more toxic than the chlorine in your water. Most experts actually believe chlorine causes virtually none of the damage in tap water. Instead, it's predominantly due to these DBPs.

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You'll also find other hidden toxins in your tap water like arsenic, cadmium, aluminum, mercury, perchlorate (primary ingredient in rocket propellant), various pharmaceutical products, and polonium-210 (radioactive element that decays into lead).
And what about that lead?
While most homes today have PVC pipes, even modern faucets have lead-containing joints that potentially contribute to lead in your drinking water.
So, the bottom line here is your tap water coming straight from its source can contain chemicals and byproducts harmful to your health.
And if you have a well, you should know that...
Your Well Water isn’t completely immune from hazardous contaminants and toxins.
However, ground water pollutants can also seep into this water source. And because private wells are shallower than water receptacles used for public water supplies, there can be a greater potential for contamination and toxic pollutants -- especially from pesticides and herbicides sprayed on lawns and farmlands.  Fecal coliform bacteria like E. coli are the most common contaminants potentially found in well water.    Septic fields are typical sources for such contamination by way of animal or human wastes. Nitrates from animal or human wastes or fertilizers are also commonly found -- along with lead, radon and other chemical and biological toxins.  So, if you have a well, you're not out of the woods from potential drinking water contaminants.  The good news for you is there are ways to remove and filter out contaminants right from your faucet. So, it doesn't matter whether you have a municipal source of water or a well.
Your personal checklist to get the clean and refreshing drinking water you deserve.
    So, what can you do to ensure healthy drinking water for you and your family?   Well it seems very clear from just about every angle your best option would be to filter your water at home with a high quality filter.  After carefully thinking of this issue for well over a lifetime it is very clear to me that the most cost effective and practical solution for nearly every family is to use a high quality water filter in your home.  But there are a number of crucial issues about filters in order to select the best filter AND to use it to remove the maximum amount of DBPs to protect you and your family.  One of the key components in a home filter system is that it should remove fluoride for the reasons discussed above.  Unfortunately most all carbon based filters do not remove fluoride.
Here are my other recommendations that should be on your checklist:
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Filter out fluoride and chlorine -- Absolutely no exceptions on these!
Remove inorganic contaminants like lead, aluminum, mercury, iron, sulfur, and lime scale
Remove organic contaminants like herbicides, pesticides, THMs (disinfection byproducts), and Volatile Organic Compounds (VOCs) that may effect the quality, odor, and taste of your drinking water
Create a bacteriostatic environment -- Must remove bacteria from the water
Be environmentally smart and help conserve water and energy
Deliver a low cost/gallon filter ratio (inexpensive) and be very easy to install -- No drilling, cutting, or need to call your plumber to get up and running.
Warning:  Most carbon filters are contaminated with aluminum.
Most people do not understand that there is an enormous difference in the quality of the carbon or charcoal that is used in filters.  Most carbon filters are actually heavily contaminated with aluminum and are leaching aluminum into the water you filter.
Fortunately if you know a few facts you can easily choose a filter that is not contaminated.
It turns out the best charcoal media to use is from coconut shells. It is the highest quality and the one with the least amount of aluminum.
The second key is to make sure that the charcoal is acid washed as this will remove most of the aluminum in the charcoal. Ideally your filter should be acid washed and be made from coconut shells but make sure it has at least one of them to avoid the aluminum issue.
Warning:  Filter your water slowly to reduce DBP’s.
Hopefully you are fully aware of the danger of disinfection byproducts (DBPs).  As I said above, chlorine is relatively non-toxic to you and your family but the DBPs are 10-100,000 times more toxic.
Most carbon filters do NOT do a good job of filtering these dangerous DBPs from the water UNLESS you filter very slowly. You see, unlike chlorine, the filter's ability to remove DBPs from the water is directly related to the rate at which the water has time to contact the media. The longer the exposure the more you will remove.  If you run the water full force through your filter you will simply let these dangerous DBPs pass right through the filter into your drinking water.  So the trick is to turn the faucet on as slow as you can tolerate.  I would strongly recommend below one gallon per minute. But the lower the better.  Trickling the water in as slowly as possible is simply your best choice for using a carbon filter.  Failure to do this will nullify the vast majority of the benefits of the filter.
Good Better and Best Options

After carefully researching this topic for many years I have reached the conclusion that there are three primary ways to filter high quality water for your home. I am going to exclude any technologies that actually restructure the water or adjust pH as that is a topic for an entirely different discussion.  
Good:  Carbon Filter System:
Pros:
Removes chlorine, inorganic, and organic contaminants
Generally easy to install yourself without the need for a plumber
Wide range of prices from under $40 to over $400
Cons:
Ineffective in removing fluoride
Most carbon filters contain aluminum
Can be a breeding ground for bacteria and affect water taste
Short to limited life on filter cartridges
Better:  Reverse Osmosis System:
Pros:
Superior to standard carbon filter as RO actually integrates carbon filter as part of its total filtration system
Most systems remove chlorine, inorganic, and organic contaminants.
Effective in removing fluoride and DBPs
Cons:
Requires costly and extensive installation -- drilling into your sink area, cutting into pipes, and hiring a plumber to get you up and running. Most people require a plumber to install.
Often needs up to 3-5 gallons of water to produce a single clean gallon -- very inefficient
Makes water acidic -- You can add a high quality salt like Himalyan sea salt to compensate for this  The dose is about 14 teaspoon per gallon.
Can be breeding ground for bacteria -- storage tank issue
Tend to destructure the water. Can restructure the water by placing in a glass container in the sunshine or with the proper use of magnets.
Copper Zinc Filter System
Pros:
Combines with carbon system for extended life
Efficiently removes fluoride, chlorine, inorganic and organic contaminants
Maximizes DBP removal when filtration rate slowed to 1-2 gallons/minute
Creates bacteriostatic environment to prevent bacteria from thriving in the overall system
Installs easily in minutes to your sink faucet -- no plumber needed
Delivers the lowest cost over the long term and the best value for you and your family in challenging economic times.
Cons:
Initial cost typically higher than standard carbon system
Needs separate fluoride filtration cartridge
There are many good water filtration systems in the marketplace. But many only satisfy certain portions of the selection checklist. 
I personally have a Berkley which does an excellent  job for me. You can always check out your personal preference and  make sure and choose one that is gravity flow. I also have a Cadium for emergency or survival in the outdoors. It will purify approx. 13,000 gallons of water or until you can reach sufficient quarters for other ways of survival. For educational purposes only.