This is because the most common hardness salt, calcium bicarbonate, is alkaline in nature.

The resin removes the calcium bicarbonate, leaving behind all the essential trace elements.

This acid comes into contact with underground marble and partially dissolves creating calcium bicarbonate.

Carbonic acid will transform calcite into more soluble calcium bicarbonate.

The shells are made of calcium bicarbonate and are secreted by the mantle.

Let's look at calcium carbonate and calcium bicarbonate, for example.

(If it's not, either you didn't use enough dry ice, or you don't have enough water to dissolve the calcium bicarbonate.)

(The calcium bicarbonate is partly why mineral water tastes good.)

If co2 is bubbled through lime water for longer time will the milkyness disappear due to formation of calcium bicarbonate?

Due to the risk of calcium bicarbonate, tap water is unsuitable.