Assuming that NaOCL and CaOCL produce the same "available" chlorine, your estimate is about what I came out with. I calculated that it would take 1.5 gallons of 5.25% bleach to equal one pound of 65% CaOCL. I looked at the price of CaOCL on InTheSwim.com and it was $130 for 50 pounds. So using the conversion above it would take 75 gallons of bleach to have the same available chloine as 50 pounds of 65% Calcium Hypochlorite. At $1.70 a gallon it would cost $127.50 for the equivalent amount of bleach. So assuming my math is correct, it should not cost me much more to use Calcium Hypochlorite for a while.

Let me know is anyone sees a flaw in my math.

Jim