Are bisulfates and bicarbonates soluble in water? Generally, are bisulfates and bicarbonates soluble in water? 
Specifically, are calcium hydrogen carbonate and magnesium hydrogen carbonate soluble in water?
According to it's Wikipedia page, calcium bicarbonate is not a known solid compound, but it does exist in solution, presumably prepared by dissolving calcium carbonate and bubbling carbon dioxide through the solution until bicarbonate dominates the following pH-dependent disproportionation:

$$\ce{2HCO3- &lt;=&gt; H2O + CO2 + CO3^2-}$$

It apparently has a solubility of 16.6 g per 100 mL of water at room temperature. which is about a 1 M solution. 

Magnesium bicarbonate similarly exists only in aqueous solution, though it is much less soluble at 0.077 g / 100 mL.

As solids, these salts probably fall victim to the following equilibrium( $\ce{M}$ is a generic divalent metal:

$$\ce{M(HCO3)2 &lt;=&gt; H2O + MCO3 + CO2(g)}$$

The carbon dioxide escapes, preventing the system from ever staying at equilibrium.