Chemistry - practical application?

You will not lower your cost. First, you have left out the other ingredient in bleach which is sodium hydroxide (red devil lye). That will increase the cost. But just using your numbers, a gallon of bleach has 226g of active ingredient. Your $9 only buys 218 g of active ingredient (about the same). So your way will will be 6x the cost. The reason it is more expensive is that in a pool, you want the active chlorine to react slower. That is why it costs more.

Make it in greater quantity. If you study business then you know that with quantity comes lower prices. That is why when a new game system is on the market its costs an arm and a leg, wait a month or 2 and the price drops by 10-20% because of overstock.

particularly frankly, lots of the "moist chemistry"-kind qualitative diagnosis schemes have been replaced by utilising extra state-of-the-paintings approaches including atomic absorption spectrometry. in spite of the fact that, any analytical scheme serves one properly in such aspects as forensic criminal examine.