How high will rocks actually raise my pH?

[Matt724]

I hear about how if you do the vinegar test on rocks you find in your backyard and it fizzes then it will raise your pH. Well, I understand, but exactly how high will it raise my pH? I have tons of rocks that I've found and 70% fizzed when I tested them using pH down and sulfuric acid. I really want to use them in my Central American tank, but obviously don't want the pH getting too high. So does anyone know what pH it usually raises to? or does it just keep raising until it reaches 14 (max on the pH scale i think.. thanks honors chem)

 

[hydrophyte]

I imagine that as important will be the effects on GH.

The degree to which the rocks dissolve in the tank water will be influenced by a number of variables, such as total volume of rock, shapes of stones, beginning water chemistry, kinds of rock and so on. I have understood that many Central Amercian fish coem from waters with somewhat higher pH and hardness. I am guessing that so long as you do not use many rocks that will begin to dissolve fast that it should be OK, especially if you can maintain frequent partial water changes.