Hey FishLore. I apologize if this is not the correct place for this post, but I was not sure where else to ask this question. I bought some small rock pieces from my LFS for my 45 gallon and ran an acid test on them after soaking them in hot water. A few places on on only a few of the rocks fizzed. I heard the sound more than anything else - it was soft, nothing dramatic and barely noticeable, and it took several minutes for any bubbles to appear even when soaking. The rocks were rather dusty when I picked them up, so could it be that organic matter might be playing a part in the reaction? If not, to what extent will these small rock pieces affect my pH? The water is soft and its pH as of now is slightly less than neutral due to the driftwood in the tank. Thanks in advance.