Dichlor/trichlor????

[Ohm_Boy]

Yup.

Di-chlor is stabilized chlorine, typically in granular form. It's easy to broadcast, dissolves fairly readily, adds chlorine and cyanuric acid (cya) to the pool.

Tri-chlor is stabilized chlorine, generally in tablets, or pucks. Dissolves more slowly so it's suitable for floater use. It adds chlorine and cyanuric acid to the pool.

Bleach, or sodium hypochlorite, is non-stabilized chlorine. Laundry variety is typically 5.25 to 6 percent strength (pool store stuff may be 12% at full strength, but it drops off easily to 8-10% over time), and adds chlorine to your pool, nothing else.

[lynnybug55]

Thank you; I understand now! One more question: Can someone give me a link to Ben's calculator I've seen mentioned here?

[JohnT]

Thank you; I understand now! One more question: Can someone give me a link to Ben's calculator I've seen mentioned here?

Not Ben's calculator, but Michael Smith's (mwsmith2) calculator.
http://home.earthlink.net/~mwsmith70/data/BleachCalc262.exe


PC only as far as I know.

[Ohm_Boy]

Beyond the bleachcalc program (which calculates much more than bleach dosages) there is Ben's "best guess" chart, which you will find as a sticky in this forum. It gives guidelines for chlorine levels and shock levels for various levels of CYA.
It's valuable because, while CYA keeps all the chlorine from going away from UV exposure, it also tends to "lock away" some amount of the total chlorine in the process, requiring more to fully sanitize at higher CYA levels. There's science... I mean... magic... or maybe magic science, involved, but Ben's chart helps to make it simple.