Simply fill container of choice with water from the tap. That’s cheap.
Alternatively, if you want a bit more flavour then you can make your own hydration drink from juice, water and a bit of salt that also helps replace some of those electrolytes lost due to sweating.
500ml Fruit Juice or 3 or 4 Oranges
Pinch salt (up to 1/2 tsp according to taste)
Sugar or honey (1-2tsp or to taste)
Simply add the juice and salt to a 2 litre hydration bladder or bottle and top up with water. Flavoursome juices work best. We’ve had good results with orange, pineapple and mango; while apple doesn’t work so well. We’re not to keen on adding any sweeteners, but you can try adding a tsp or two of sugar or honey and see how it goes, remembering that honey’s a bit sweeter than sugar so you’ll need a bit less.
Photo credit: madaise / Foter / Creative Commons Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0)
Either way, it’s much healthier for you than shop bought bottles and has no hidden ingredients, especially if you’re using decent quality juice or even make fresh juice yourself.