Why is FC still zero?

[Newdude]

I noticed that my SLAM levels is no longer at FC = 10 but significantly higher (FC = 24!) with higher CYA. Does that mean I'll need to buy and pour lot more liquid chlorine?

Probably. Chlorine burns off as a % and it's not particularly noticeable near target range but becomes really noticeable in the 20s. You'll have the regular UV to deal with, extra burnoff, and algae. The FC will just be consumed faster and it's more of a chore.

I never seem to have sufficient liquid chlorine at hand to sustain a SLAM... How many of gallons of liquid chlorine (12.5%) should I have before I attempt SLAM?

No 2 slams are the same and 10 gallons goes 2.5X further in 10k gallons than for you. But with a big pool, I'd grab 10 with clear-ish water and 12 with green water to start, plus what took to get to slam. That itself may be 5 or 6 gals

Has the water improved any or is it still green ?

 

[PoolStored]

Buy 15 gallons. You can take them back.

 

[pikachupool]

Probably. Chlorine burns off as a % and it's not particularly noticeable near target range but becomes really noticeable in the 20s. You'll have the regular UV to deal with, extra burnoff, and algae. The FC will just be consumed faster and it's more of a chore.

No 2 slams are the same and 10 gallons goes 2.5X further in 10k gallons than for you. But with a big pool, I'd grab 10 with clear-ish water and 12 with green water to start, plus what took to get to slam. That itself may be 5 or 6 gals

Has the water improved any or is it still green ?

Still green. (Less green than when I started.) I have never seen the bottom of my pool before and I don't know where the drain is located.

I've poured 10 gallons of liquid chlorine since the start of the month!

I have 4 gallons left (to pour) and I'll need to order more.

 

[Newdude]

looks like I'll need to order more.

I promise I am 100% on board with convenience. (Read.... I'm LAY-ZEE). But I'd go pick it out myself because older stash is a waste of funds and also compounds when blowing through LC.

 

[pikachupool]

Update:

I've been trying to sustain FC > 24 to maintain SLAM levels this week, with small successes.

Latest Test Result Summary:
FC: 22.5 (1 hour ago)
CC: 0.5 (1 hour ago)
pH: 7.7 (3 days ago)
TA: 80 (9 days ago)
CH: 100 (5 days ago)
CYA: 60 (4 days ago)
SALT: 2930 (3 days ago)
TEMPERATURE: 68°F (3 days ago)
==========================================
------------------------------------------
Test Results 04-25-2025 @ 06:17 PM
------------------------------------------
Free Chlorine: 22.5
Combined Chlorine: 0.5

------------------------------------------
Test Results 04-25-2025 @ 08:07 AM
------------------------------------------
Free Chlorine: 21.5
Combined Chlorine: 0.5

------------------------------------------
Test Results 04-24-2025 @ 06:45 PM
------------------------------------------
Free Chlorine: 26.0
Combined Chlorine: 1.0

------------------------------------------
Chemical Addition 04-24-2025 @ 01:00 PM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-24-2025 @ 08:05 AM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-24-2025 @ 07:59 AM
------------------------------------------
Free Chlorine: 23.0
Combined Chlorine: 1.0

------------------------------------------
Test Results 04-23-2025 @ 07:55 PM
------------------------------------------
Free Chlorine: 27.0
Combined Chlorine: 0.5

------------------------------------------
Chemical Addition 04-23-2025 @ 04:45 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-23-2025 @ 02:05 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-23-2025 @ 08:50 AM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Test Results 04-23-2025 @ 08:45 AM
------------------------------------------
Free Chlorine: 19.5
Combined Chlorine: 2.5

------------------------------------------
Chemical Addition 04-22-2025 @ 07:25 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-22-2025 @ 07:15 PM
------------------------------------------
Free Chlorine: 21.5
Combined Chlorine: 1.0
pH: 7.7
Salt: 2930

------------------------------------------
Chemical Addition 04-22-2025 @ 01:05 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-22-2025 @ 08:00 AM
------------------------------------------
Free Chlorine: 30.0
Combined Chlorine: 1.5

------------------------------------------
Chemical Addition 04-21-2025 @ 08:20 PM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-21-2025 @ 06:50 PM
------------------------------------------
+ 256 FluidOunces of Bleach

------------------------------------------
Test Results 04-21-2025 @ 03:20 PM
------------------------------------------
Free Chlorine: 9.5
Combined Chlorine: 0.5
pH: 7.5
CYA: 60
Salt: 3080
Temperature: 15°C

------------------------------------------
Chemical Addition 04-21-2025 @ 08:40 AM
------------------------------------------
+ 59 FluidOunces of Bleach

------------------------------------------
Test Results 04-21-2025 @ 08:30 AM
------------------------------------------
Free Chlorine: 8.0
Combined Chlorine: 0.5
pH: 7.8
Salt: 3130

------------------------------------------
Chemical Addition 04-20-2025 @ 07:05 PM
------------------------------------------
+ 36.81348600704059 FluidOunces of Bleach

------------------------------------------
Test Results 04-20-2025 @ 07:00 PM
------------------------------------------
Free Chlorine: 8.5
Combined Chlorine: 1.0

------------------------------------------
Test Results 04-20-2025 @ 04:45 PM
------------------------------------------
Free Chlorine: 11.0
Combined Chlorine: 0.5
pH: 7.5
Calcium Hardness: 100
CYA: 70
Salt: 2920

------------------------------------------
Chemical Addition 04-20-2025 @ 01:40 PM
------------------------------------------
+ 120 Pounds of Salt

------------------------------------------
Chemical Addition 04-20-2025 @ 12:25 PM
------------------------------------------
+ 32 FluidOunces of Bleach

------------------------------------------
Test Results 04-20-2025 @ 12:05 PM
------------------------------------------
Free Chlorine: 8.5
Combined Chlorine: 0.5
pH: 7.4
CYA: 100
Salt: 2510

------------------------------------------
Test Results 04-20-2025 @ 08:15 AM
------------------------------------------
Free Chlorine: 10.5
Combined Chlorine: 0.5
pH: 7.5
Salt: 2300

---
I clean the pool at least once a day - fishing out floating matter, clearing out my skimmer baskets.

I've also adjusted the pool eyeballs to get a circulation going.



Is there anything I'm doing wrong/improve on?

The pool is still green - only the first step is visible, everything else is still murky looking. Earlier, I had to empty out what looked like a small rat corpse from my skimmer basket.

 

[Bperry]

Update:

I've been trying to sustain FC > 24 to maintain SLAM levels this week, with small successes.

Latest Test Result Summary:
FC: 22.5 (1 hour ago)
CC: 0.5 (1 hour ago)
pH: 7.7 (3 days ago)
TA: 80 (9 days ago)
CH: 100 (5 days ago)
CYA: 60 (4 days ago)
SALT: 2930 (3 days ago)
TEMPERATURE: 68°F (3 days ago)
==========================================
------------------------------------------
Test Results 04-25-2025 @ 06:17 PM
------------------------------------------
Free Chlorine: 22.5
Combined Chlorine: 0.5

------------------------------------------
Test Results 04-25-2025 @ 08:07 AM
------------------------------------------
Free Chlorine: 21.5
Combined Chlorine: 0.5

------------------------------------------
Test Results 04-24-2025 @ 06:45 PM
------------------------------------------
Free Chlorine: 26.0
Combined Chlorine: 1.0

------------------------------------------
Chemical Addition 04-24-2025 @ 01:00 PM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-24-2025 @ 08:05 AM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-24-2025 @ 07:59 AM
------------------------------------------
Free Chlorine: 23.0
Combined Chlorine: 1.0

------------------------------------------
Test Results 04-23-2025 @ 07:55 PM
------------------------------------------
Free Chlorine: 27.0
Combined Chlorine: 0.5

------------------------------------------
Chemical Addition 04-23-2025 @ 04:45 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-23-2025 @ 02:05 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-23-2025 @ 08:50 AM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Test Results 04-23-2025 @ 08:45 AM
------------------------------------------
Free Chlorine: 19.5
Combined Chlorine: 2.5

------------------------------------------
Chemical Addition 04-22-2025 @ 07:25 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-22-2025 @ 07:15 PM
------------------------------------------
Free Chlorine: 21.5
Combined Chlorine: 1.0
pH: 7.7
Salt: 2930

------------------------------------------
Chemical Addition 04-22-2025 @ 01:05 PM
------------------------------------------
+ 64 FluidOunces of Bleach

------------------------------------------
Test Results 04-22-2025 @ 08:00 AM
------------------------------------------
Free Chlorine: 30.0
Combined Chlorine: 1.5

------------------------------------------
Chemical Addition 04-21-2025 @ 08:20 PM
------------------------------------------
+ 128 FluidOunces of Bleach

------------------------------------------
Chemical Addition 04-21-2025 @ 06:50 PM
------------------------------------------
+ 256 FluidOunces of Bleach

------------------------------------------
Test Results 04-21-2025 @ 03:20 PM
------------------------------------------
Free Chlorine: 9.5
Combined Chlorine: 0.5
pH: 7.5
CYA: 60
Salt: 3080
Temperature: 15°C

------------------------------------------
Chemical Addition 04-21-2025 @ 08:40 AM
------------------------------------------
+ 59 FluidOunces of Bleach

------------------------------------------
Test Results 04-21-2025 @ 08:30 AM
------------------------------------------
Free Chlorine: 8.0
Combined Chlorine: 0.5
pH: 7.8
Salt: 3130

------------------------------------------
Chemical Addition 04-20-2025 @ 07:05 PM
------------------------------------------
+ 36.81348600704059 FluidOunces of Bleach

------------------------------------------
Test Results 04-20-2025 @ 07:00 PM
------------------------------------------
Free Chlorine: 8.5
Combined Chlorine: 1.0

------------------------------------------
Test Results 04-20-2025 @ 04:45 PM
------------------------------------------
Free Chlorine: 11.0
Combined Chlorine: 0.5
pH: 7.5
Calcium Hardness: 100
CYA: 70
Salt: 2920

------------------------------------------
Chemical Addition 04-20-2025 @ 01:40 PM
------------------------------------------
+ 120 Pounds of Salt

------------------------------------------
Chemical Addition 04-20-2025 @ 12:25 PM
------------------------------------------
+ 32 FluidOunces of Bleach

------------------------------------------
Test Results 04-20-2025 @ 12:05 PM
------------------------------------------
Free Chlorine: 8.5
Combined Chlorine: 0.5
pH: 7.4
CYA: 100
Salt: 2510

------------------------------------------
Test Results 04-20-2025 @ 08:15 AM
------------------------------------------
Free Chlorine: 10.5
Combined Chlorine: 0.5
pH: 7.5
Salt: 2300

---
I clean the pool at least once a day - fishing out floating matter, clearing out my skimmer baskets.

I've also adjusted the pool eyeballs to get a circulation going.

View attachment 640634

Is there anything I'm doing wrong/improve on?

The pool is still green - only the first step is visible, everything else is still murky looking. Earlier, I had to empty out what looked like a small rat corpse from my skimmer basket.

View attachment 640635

Keep going. It’s only been 5 days (on your logs). How’s the filter pressure? Might try cleaning and brushing more than once per day if possible.

If the pool has been closed for long (2 years ?) and you can’t see the bottom, are you sure there isn’t a pile of junk (rotting vegetation) at the bottom? If there is, the SLAM will take a very long time. So whatever you can to get debris out of the water.

 

[pikachupool]

Keep going. It’s only been 5 days (on your logs). How’s the filter pressure? Might try cleaning and brushing more than once per day if possible.

I did consider that: it was cleaned when I opened my pool on March 27. I don't track the filter pressure closely. It's usually hovering around 1.5?

I believe the filters themselves were installed sometime in 2021.

 

[Bperry]

I did consider that: it was cleaned when I opened my pool on March 27. I don't track the filter pressure closely. It's usually hovering around 1.5?

I believe the filters themselves were installed sometime in 2021.

I edited my post with a couple more questions. You need to clean the filter and then note the pressure when it’s clean. Then clean it again whenever the pressure rises by 25% more than the “clean” pressure.

1.5psi sounds pretty low. Might want to check that water isn’t bypassing the filter.

 

[Newdude]

I think you're doing awesome on maintaining the FC, but you're spinning your wheels until all the floor muck is gone

How are you cleaning the pool ? Manual vac, robot, brushing only ?

 

[pikachupool]

I think you're doing awesome on maintaining the FC, but you're spinning your wheels until all the floor muck is gone

How are you cleaning the pool ? Manual vac, robot, brushing only ?

I have a robot vacuum - always dirty when I clean the filters after a good day's work. Manually fishing out anything that's floating at the end of the day. I'm probably not brushing enough.

 

[Newdude]

Robots aren't well suited for this task. That crud needs to go ASAP and although the robot will eventually get it all on pass 176, you're maintaining slam until then.

I watched my swamp go cloudy blue within 2 or 3 mins of getting the last bit of crud out. I couldn't see the floor and little by little I could see more until finally there was a small patch over there that I somehow missed. It might have only been 30 seconds later, it was like somebody flipped a switch.

That wasn't the end of the battle, it still took days of filtering, but it was the turning point with the green gone.

 

[pikachupool]

Robots aren't well suited for this task. That crud needs to go ASAP and although the robot will eventually get it all on pass 176, you're maintaining slam until then.

I watched my swamp go cloudy blue within 2 or 3 mins of getting the last bit of crud out. I couldn't see the floor and little by little I could see more until finally there was a small patch over there that I somehow missed. It might have only been 30 seconds later, it was like somebody flipped a switch.

That wasn't the end of the battle, it still took days of filtering, but it was the turning point with the green gone.

What's the best way to see (the pool floor), and remove any stuff that's on the pool floor? Is there anything I can rent perhaps?

My pool depth is apparently a gradual 3.6 ft to 7.5ft (claimed by the builder, I've yet to verify with a tape).

 

[Bperry]

What's the best way to see (the pool floor), and remove any stuff that's on the pool floor? Is there anything I can rent perhaps?

My pool depth is apparently a gradual 3.6 ft to 7.5ft (claimed by the builder, I've yet to verify with a tape).

I use a “pool leaf rake” and it works well but is time consuming. Walmart has them. You’ll have to blindly scoop.

 

[Newdude]

What's the best way to see (the pool floor), and remove any stuff that's on the pool floor?

Blindly vacuuming with a manual vacuum. (the hose and pole kind). Eventually you'll get enough out, along with the FC being at SLAM, and you'll be able to make out the floor.

The robot will get there too, but will take many more attempts at it.

My pool depth is apparently a gradual 3.6 ft to 7.5ft (claimed by the builder, I've yet to verify with a tape).

4 to 8ft wall height is a common build. The floor slope is however the customer wanted.