- Thread starter Leslie_mss
- Start date

The milky white is probably calcium but we can't really say without a full set of test numbers. Can you post a full set of test numbers, the size of your pool?

sticky.php

I know that a lot of research went into these numbers. It may be too accurate to refer to it as a "guess" chart.

By the way, the basic rule that works pretty darn well (except for 0 ppm CYA) is that the Min FC is 7.5% of the CYA level, the Target FC is 11.5% of the CYA level, the Yellow/Mustard Min FC is 15% of the CYA level, the Shock FC is 40% of the CYA level, and the Yellow/Mustard Shock FC is 60% of the CYA level.

Richard

Richard

There is really a more complex optimization going on. You want to also balance the total cost of the chlorine over time. 100 ppm is wasted on regular green algea. The mustard algae level is higher because adding more at once really helps, while going to that level for green algea would be excessive. I suppose that with mustard algae you are also a little more desperate, even if you don't know it yet, so it is worth taking a little more damage risk.

So we are trying to balance at least effective dosage, damage risk, amount of work, and measurement variability all at once.