I purchased me new Betta Richie for my 6.6 gal tank last Thursday. When I tested the water that he came in the PH was 8.2, so I cleaned the tank and put fresh tap water in for him with the same PH to avoid shock. I want to use the bottled spring water that I have for him instead that has a PH of 7. How can I change over and use the spring water without shocking him? I read that a PH change of greater than .2 can cause shock. Thank you.