Alkaline green tea in bags and lemon water from concentrate?

I've heard that both green tea and lemon water are two of the most alkalinizing drinks. This was regarding the usual green tea and a lemon water that is made from a fresh lemon squeezed into water. But what about alternative ways of getting green tea and lemon water?

For example, I never brew my tea, and make it from tea bags instead. More than that, I don't like drinking the usual tea with caffeine and much prefer decaffeinated. Does the tea still have its alkalizing effect or is it lost during the decaf process? Any preferences on whether drink it hot or cold?

Regarding lemon water - does it have to be made with a freshly squeezed lemon or is the alternative of buying concentrated lemon juice (it's usually sold in green bottles) just as good?

Also, if anybody can recommend a good green/herbal non-expensive tea specifically for the purpose described, I'm also interested to hear your opinion. Something that is easily accessible in food stores.

Thanks.

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