I picked up a bottle of this (dry version) the other day to bring my pH to 7.0 from about 7.5ish. I got home and put it dissolved it in a cup of water then added it to my tank (fishless). The next day I went to the store where I had purchased it and the guy said it doesn't actually lower the pH and he tested my water while I was there and said my pH was still about 7.5. I tested it myself when I got home and he was right, it didn't lower my pH. So what's the problem ? Does it not bring your pH to 7.0 like it says it will ?