Spring water is considered the healthiest water to drink because it contains essential minerals such as calcium, magnesium, sodium, and potassium. As the name implies, the water comes from a spring or an underground source. It is the purest form of water since it is natural and organic without any treatment.

Since spring water is pure and organic, it has a natural alkaline level of greater than 7. You can find spring water in bottled form, but verify the source to ensure that it comes from a spring and has a high mineral content. 

Spring water is among the healthiest water to drink because it offers several benefits. It is naturally purified from an underground source, which means it is free of harmful contaminants like lead and chlorine. Since it does not undergo added filtration before bottling, it retains the beneficial minerals in the water. 

The high electrolyte level in spring water makes it an ideal choice for athletes because it offers extra hydration benefits. Meanwhile, it contains no additives, so you won't have to worry about any harmful side effects. 

Mineral water is often confused with spring water. However, these two are different from each other. Mineral water is directly collected from an underground source (like spring water) and contains 250 parts per million of minerals from dissolved solids. 

Since the source is a protected mineral water spring, it is abundant in natural minerals like calcium, magnesium, sulfate, and bicarbonate. It has a distinctive salty taste because of the presence of minerals. 

The most crucial benefit of mineral water is its ability to boost muscle growth and improve bone density because of its rich calcium content. And like spring water, it is directly collected from the source, so it won't require further treatment or alteration. 

The above two types of water are derived from natural sources and undergo no treatment. The rest of this list is water undergoing treatment or filtration. Some claim that filtered water is no longer “healthy” because it also filters the essential minerals in the water that offer it its health benefits. Therefore, they are ranked lower on this list because they lose some of their health benefits due to the filtration of the mineral content.

With that said, distilled water is one of the healthiest waters to drink since it has been treated through a process known as distillation. The distillation method involves boiling the water until it turns into vapor. The vapor is converted into liquid form through the condensation process. It undergoes several purification processes to remove harmful contaminants from the water, ensuring it is safe to drink.

The biggest concern is that while distilled water is safe to drink, is it still healthy? Does the purification process wipe out the essential minerals from the water? 

Distilled water is the safest choice for drinking water if you live in an area with an unknown source of tap water. It is also a good alternative if you live near manufacturing plants, as these facilities could pollute the water source. However, distilling water means it loses most of its mineral content and hydrating abilities. 

Purified water is a general term for water undergoing any purification method. The source could be underground, surface water, or tap water. Various purification methods apply for purified water, such as distillation, reverse osmosis, ozonation, or absolute one-micron filtration. Regardless of the purification method, you can expect no impurities in the water, such as bacteria and parasites. 

Many bottled water companies use multiple treatment techniques to remove water impurities. It is a good choice for areas with contaminated water sources. But like distilled water, safety is no longer the concern but more a lack of mineral content. The purification process could potentially wipe out the minerals and electrolytes in the water that bring health benefits to the body. 

Alkaline water has a higher pH than tap water, at 8 or above. The neutral pH level is 7. 

Alkaline water ranks as one of the healthiest waters to drink because it contains properties that fight free radicals in the body. Those free radicals cause inflammation and other chronic diseases. Alkaline water promotes oxygen distribution throughout the body. The high pH level in alkaline water is due to the high calcium, bicarbonate, and magnesium content. Therefore, your body can enjoy the benefits of these minerals when consumed.

The downside of alkaline water is that it could alter stomach acid levels. It could also lower the body's natural pH level. 

Reverse osmosis is one of the most common filtration methods to purify drinking water. Therefore, this type of water ranks among the healthiest to drink because it eliminates hazardous contaminants, such as lead and arsenic.

Reverse osmosis is highly effective in treating drinking water, so it is heavily used in home water treatment units. However, like most purification methods, there is a concern that the filtration process could also wipe out healthy minerals from the water. Some commercial bottled water manufacturers claim they use remineralizes to enhance the mineral content of the water, but these processes require further research to support their effectiveness.

Structured water completes this list of the healthiest waters to drink. It undergoes a process that alters the structure of the water into a hexagonal molecule cluster. The resulting water is almost as pure as water that is not processed.

The restructured molecules in the water provide various health benefits, such as extra hydration for the body. It delivers longer lasting hydration than ordinary water.