Editing my post, to add that you can ignore, I had only read page one of the thread, obviously I am way behind.
I am the newbie on the board, been doing this for 5 months, and sometimes my advice helps those who are totally new. Here goes....
The other good reason is it OK and wise to "round up" your CYA to 40, is that you will find it can take several days after adding stabilizer for the CYA reading to become totally accurate. It will continue to rise until all the granules are dissolved.
Now, regarding bleach, you will likely need quite a bite, so get a good deal on it. There are a few things to consider. First is the concentration of Sodium Hypochlorite. What you are really adding to your pool to achieve shock is the Sodium Hypochlorite. I have seen everything from 8% to 12.5%. If you use 12.5%, you are effectively adding 50% more FC to your pool water than if you use 8%. The pool calculator has an entry for concentrate, to help make the correct calculations. Walmart near my house has 10% for $2.88 a gallon. Menards near me, has 12.5% for $2.99 but it is a further drive. I did stock up when Menard's had theirs by one get one for a smoking $1.50 per gallon of 12.5%.
Good luck, you will be amazed at what happens to your pool!