10.3%, and used 1/2L 2.15hrs ago
I would estimate your 22x12, 48in pool at about 6900 gallons / 26000 liters. According to
PoolMath, 500mL of 10% liquid chlorine in that volume of water would raise FC by 1.9.
You are likely consuming about 4ppm of FC per day this time of year. So you should probably be adding at least twice the amount you added on a nightly basis (1L).
At a CYA of 40, you never, ever, want your FC level to go below 3. 5 to 7 is ideal. (
FC/CYA Levels)
I would test the FC level now, and then add enough to get up to 7ppm.
If you're at 1-2, I'd add 1.5L
If you're at 3-4, I'd add 1L
If you're at 5-6, I'd add 0.5L
Then, do that each night. But you should never be below 3ppm when you test. If you are, you'll need to look at raising your target or bumping your CYA a small amount.