Water is perhaps the single most important item you can have with you when you are out in the wild. Water also is one of the worst items to carry as it is so heavy. Putting water bottles or a thermos into a backpack works well enough, but if you want an even more economical approach, a hydration pack is a great way to carry water in the wild. Not only is the weight evenly distributed across your back, but you can drink through a tube rather than taking the whole thing off to get a drink.
Having said that, here is a list of the top 5 most popular hydration packs currently on Amazon (as of July 2014).
This lightweight bag holds 2.5 liters of water and is 17″ x 8″ x 5″. It really is fairly durable and has a pocket to store some stuff (maybe a snack and some survival gear?) The bag is made of really heavy duty materials and should hold up to a lot of abuse. People have complained that the hose just dangles. The bladder is easy to fill up. Get it here (ad).
This bag is from Camelbak, the leader in hydration bags, and is from 2011 (the 2014 model is at #3 below). This 50 ounce bag (1.5 liters) is 16.5 x 11 x 3.5 inches. It boasts HydroGuard technology to inhibit the growth of harmful bacteria and prolong reservoir life, a PureFlow tube, the Camelbak patented Big Bite Valve for easy drinking, and an easy-to-clean wide-mouth opening. This bag would be great if you only wanted to bring a small amount of water, but many people who buy it complain that it doesn’t hold enough for them. There is a small pocket to carry some extra gear, but not much. You can buy this bag here (ad).
Another top of the line bag from Camelbak, this hydration bag is the new Camelbak for 2014. This bag carries 50 ounces (1.5 liters) and is 13 x 7 x 3.5 inches. This bag is very similar to the last one in that it uses all the Camelbak tech like the Big Bite Valve and HydroGuard technology to keep the reservoir clean and healthy. This bag supposedly distributes the weight a little more even than past bags and the pocket is slightly bigger. You can buy this bag here (ad).
This 70 ounce bag from Teton is really a steal at the current price point. It’s lightweight, holds more water than the Camelbaks, and has a bigger pocket, all for a lower price. There is a barrel lock and FDA approved bladder. This bag is made of good materials and is comfortable to wear. You can get this bag here (ad).
This 70 ounce hydration pack from Ispeed is 17″x2″x7″ and has a BPA free, FDA approved bladder. There is a small stash pocket and the bag is comfortable to wear. The materials also clean and dry off really well. The pipe unscrews, which is nice for cleaning. Some people have complained about the bite valve leaking, which can be a problem over time. The valve does have a clip on it, so if it does leak you can always clip it facing upwards to it stops. This bag is really a deal at it’s current low price, which is why it is the most popular bag on Amazon right now (ad).