2nd reading, what happened?

Winger 03

Well-known member
Sep 7, 2009
Frederick County, MD
I really thought I was going right, then I got some strange readings today.

Previous Readings (last Sunday)
FC: 2
CC: 0.5
TC: 2.5
PH: 7.5
TA: 110
CH: 180
CYA: 0

Low CYA, so I took a baby step of adding 4 lbs of 96% CYA (HTH from WalMart) via sock in front of a return early last week.

Today's readings are really a mystery to me, specifically the FC.

FC: 18
CC: 0
TC: 18
PH: 7.5
TA: 130
CH: 160
CYA: 20

We are having a rock path laid leading to the pool, so I left the solar cover on for the past 4 days or so to keep the dirt down and we have not been in since last weekend. I did hit the "boost" button a couple of days ago on the SWCG after the CYA was in to push up the chlorine a bit as I needed to get more FC in since I now had some CYA.

I did the FC test 2x so I am pretty sure I did it right.

I am going to take the solar cover off to let the sun burn off a little chlorine, but I could also use a little advice from the masses here.

I am also a little confused by the recommended levels as called for in the Pool Calculator. They do not seem to match up with what is suggested in the threads. If someone can post recommended levels, I will begin to aim for them.

Thanks in advance.........


TFP Expert
LifeTime Supporter
Nov 5, 2008
Sounds like Boost plus cover equals a lot of chlorine.

The increase in CYA would have helped you to keep the chlorine generated while the cover was off. I don't know what your target was for the 4 lbs but even if it is not showing on test you know it is in there. So with the CYA higher you may have been retaining more of the chlorine, then you went to Boost and covered up for 4 days. I don't know what you can produce on Boost but with the cover on you didn't lose any of it.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
The solar cover is helping you maintain a high FC level. When you remove the cover things will be very different.
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