High PH in freshwater tank

Question
Hello...I have a 49gal freshwater tank and while I was away for a few weeks, my husband decided that the ph was to low so he added baking soda to my tank, the ph is now at 8.2. Am I correct in my thinking that I need to change 5 to 10 gal. every other day to get this to lower. I had to stop him from putting battery acid in my tank to lower it. I have a R.O. system and that is the only water I use. Please advise, I don't want my fish to become little corpses.

Answer
Diane,
Without know what types of fish are in the tank, it is hard to tell if the ph is too high. Usually, Ph is not as serious as ammonia or nitrites. Fish do become accustomed to Ph levels. Please NO BATTERY ACID. I almost fell off my chair when I read that. You can either lower the Ph by doing the water changes or by using a product called Ph down. API make a great product that I hear works very well. Let me know what types of fish are in your tank.