Am I reading this table correctly though that with my CYA at 40, in an ideal PH, I would have a 5-7 for FC?
Yes. Now what does that mean ?
If you test a 6 FC today, are we good ?
Well. That depends on the time of day.
If you're losing 4ppm a day in July, and it's the morning before the daily loss hits, 6 FC isn't going to cut it because you land at 2 FC by sundown.
If you're losing 4 ppm a day in July, and it's the evening after the daily loss occurred, then you're golden landing at 6 FC. But here's the thing. You may need to dose over target, to allow the higher daily loss of the peak season.
Morning or evening, if you need to dose to 10 to land at 6, then so be it.
In the early/late season, targets get lowered to reflect the 2 or even 1 FC daily loss. 10 could be a week-long dose in April and only 1 day in August.
Your UV loss is more or less a bell curve across the season and you will know what its been recently with regular testing.
Put another way : (1000 words)
