Tried here? 
Although personally I don't like using it. If your water is acidic, It can quite frequently not contain enough calcium and other elements essential for snail shell growth. I would presume that's why you always see snails grow faster in harder more alkaline water (or at least they seem to) and why perfect pH 7 RO water is useless unless you are adding the right minerals for them.
The reason the pH raises with Baking Soda (Sodium Bicarbonate) is that it brakes down into Sodium and Bicarbonate ions, most of the Bicarbonate then brake down further into CO2 and Hydroxide. The majority of the CO2 usually gasses off before it forms Carbonic acid, and since Hydroxide is mildly alkaline this raises the pH.
The remaining Bicarbonate buffers the water against relatively small pH changes (so bogwood or limestone in your tank shouldent affect pH).
Problem is if you run out of Baking Soda and need to do a water change, your pH is affected a lot depending on how much baking soda you had to use to raise the pH above 7.
The second thing is, the buffer doesn't work for ever. If you were simply to go without water changes, the pH would quickly start to change (depending on what's in the tank).
Adding Sodium Bicarbonate doesn't do much help to snails other than preventing the shells corrode in the acidic water (it provides Sodium, but this is of relativity minor importance).
The best way to increase the pH in your tank is something like sea shells, crushed coral or even limestone (all provide calcium).
Calcium is the most important element you have to provide for healthy shell growth. The other elements that invertebrates in general need are usually present in large enough quantities in tap water (enough for freshwater inverts anyway). However, it's always good to provide extra of these, and IME it can speed up growth and bring out nice markings in things like tadpole snails (mine now all have a lovely greenish mother of pearl sheen).
My preferred way of doing this is using Kent/red sea reef supplements.
The best supplement IMO is Red Sea Calcium +3, since it's pretty much all you would even dream of adding in one bottle, where as if you went the kent route you would spend more on buying more bottles.
But remember never to rely on these additives, they are called supplements for a reason
.
/www.applesnail.net/phpBB2/viewtopic.php?t=3988
