There's really nothing to do before switching to the BBB method. As Bleach isn't any different from what you buy at the pool store (except its cheaper, doesn't add any unnecessary chemicals to your water, its still chlorine). I did the same thing at the beginning of this swim season, purchase a $150 bucket of Dichlor and went through it pretty fast, as I found out that the Dichlor was raising my CYA levels and causing me to have to use more of it to keep the water clear. I do go through a lot of bleach but that's currently due to my CYA levels being over 100 and I'm in AZ where its currently at least 110 degrees daily. You won't regret converting I promise you! My pool is the clearest its ever been now, no more scale on the tiles or anything. I'm constantly getting compliments on my pool when we have people over!