- Jul 18, 2022
- 9
- Pool Size
- 60000
- Surface
- Vinyl
- Chlorine
- Liquid Chlorine
Hi All,
I've been trying to resolve an issue with green algae in my pool. For the past couple of weeks I've been following the SLAM guidelines documented here to the best that my schedule allows and don't seem to be making any progress. The pool isn't getting worse but it's not getting better.
Attached is an image of what the pool looks like. Ignore the rough shape of the structure and liner. This thing is on its last legs!
Levels before beginning the SLAM were:
FC: 0.6
CC: 0.2
pH: 7.7
TA: 90
CH: 250
CYA: <30 (best guess 20)
Note: When needed, the pool is refilled with well water. The water runs through a softener but there's no way it keeps up during the full pool fill. Unsofened, the water is:
Iron: 0gpg
Hardness: 25gpg
I first lowered the pH to 7.6 with Muriatic Acid. Confirmed with test.
Then I started to SLAM.
General schedule:
- Test first thing in the morning
- Test at ~8pm at night
- Manually vacuum from ~8pm-9pm most nights
- Empty strainer basket 1-2 times per day as needed
- Backwash filter and empty pump basket every 2-3 days as needed
Action log (rough at the start but gets more detailed as we go!)
Day 1-2: I added a total of 10.4 L of 10.3% bleach to keep FC at or above 10. After the first day the FC never tested below 12.
Day 3-6: I went through 7.4L of 10.3% bleach to keep FC above 12 and CC dropped to 0.1.
Day 6-9: I ran out of bleach and didn't have access to a car for 3 days so I added 800g of Trichlor pucks spread over those days to try and keep FC up. I figured (mistakenly?) that I could use some more CYA anyway so it wasn't the end of the world. During this time the FC crept up to 16.5 but the CYA didn't noticeably.
Day 9-10: Once I had a car again I picked up some dry CYA and a bunch more bleach. I added 400g of dry CYA and continued maintaining FC with bleach. Once the CYA disolved this is where my values were at:
FC: 16.5
CYA: 30
With the increase in CYA I decided to target an FC at no lower than 14 for each test. Just in case something came up and I missed a morning or night test.
Day 11: FC at 14, Add 3.6L of bleach
Day 12: FC at 17.5 in the morning and 17 at night (a really cloudy day with rain coming at night)
Day 13: FC at 15 in the morning, add 3.6L of bleach. Got home too late to test but added another 3.6L of bleach at night.
Day 14: FC at 14 in the morning, add 3.6L of bleach.
At this point I'm starting to wonder if maybe I have mustard algae?
Backwashes of the filter are pretty green but clear up much faster than I've seen when the filter is really full.
When vacuuming during the early days of the SLAM the water running through the pump was quite green and I did vacuum up quite a bit of white flakes (calcium?). Probably a pump basket worth.
I'm betting the flakes came from my previous attempt to open the pool where, at the advice of then local pool store, I burned through ~3Kg of Cal-Hypo about a week trying to get rid of the algae before finding TFP and getting a proper test kit.
I think I've been pretty thorough reading through existing forum posts, understanding the tests (including Taylor K-2006 manual), and read through the Pool School posts here. We really haven't been able to enjoy the pool at all this year and I'm starting to run out of ideas. Maybe someone more experienced than me sees a glaring issue or has advice on the best course of action?
Otherwise I think my options are one of the following:
- Raise FC to try a mustard algae shock
- Drain the pool down to the return and deep clean the sand filter.
- Drain the pool completely, pressure wash liner, re-fill. The pool is so old I'd be worried about the liner shrinking/drying out and breaking it. If it did work, I'd probably call it for the season and try again next summer.
- Ditch the pool and think about getting in line to get a new one in a few years (current wait time is ~2-3 years).
- The pool is getting long in the tooth (~15 years) with some uneven pits in the floor of the pool and liner slipping on the sides in some places.
I've been trying to resolve an issue with green algae in my pool. For the past couple of weeks I've been following the SLAM guidelines documented here to the best that my schedule allows and don't seem to be making any progress. The pool isn't getting worse but it's not getting better.
Attached is an image of what the pool looks like. Ignore the rough shape of the structure and liner. This thing is on its last legs!
Levels before beginning the SLAM were:
FC: 0.6
CC: 0.2
pH: 7.7
TA: 90
CH: 250
CYA: <30 (best guess 20)
Note: When needed, the pool is refilled with well water. The water runs through a softener but there's no way it keeps up during the full pool fill. Unsofened, the water is:
Iron: 0gpg
Hardness: 25gpg
I first lowered the pH to 7.6 with Muriatic Acid. Confirmed with test.
Then I started to SLAM.
General schedule:
- Test first thing in the morning
- Test at ~8pm at night
- Manually vacuum from ~8pm-9pm most nights
- Empty strainer basket 1-2 times per day as needed
- Backwash filter and empty pump basket every 2-3 days as needed
Action log (rough at the start but gets more detailed as we go!)
Day 1-2: I added a total of 10.4 L of 10.3% bleach to keep FC at or above 10. After the first day the FC never tested below 12.
Day 3-6: I went through 7.4L of 10.3% bleach to keep FC above 12 and CC dropped to 0.1.
Day 6-9: I ran out of bleach and didn't have access to a car for 3 days so I added 800g of Trichlor pucks spread over those days to try and keep FC up. I figured (mistakenly?) that I could use some more CYA anyway so it wasn't the end of the world. During this time the FC crept up to 16.5 but the CYA didn't noticeably.
Day 9-10: Once I had a car again I picked up some dry CYA and a bunch more bleach. I added 400g of dry CYA and continued maintaining FC with bleach. Once the CYA disolved this is where my values were at:
FC: 16.5
CYA: 30
With the increase in CYA I decided to target an FC at no lower than 14 for each test. Just in case something came up and I missed a morning or night test.
Day 11: FC at 14, Add 3.6L of bleach
Day 12: FC at 17.5 in the morning and 17 at night (a really cloudy day with rain coming at night)
Day 13: FC at 15 in the morning, add 3.6L of bleach. Got home too late to test but added another 3.6L of bleach at night.
Day 14: FC at 14 in the morning, add 3.6L of bleach.
At this point I'm starting to wonder if maybe I have mustard algae?
Backwashes of the filter are pretty green but clear up much faster than I've seen when the filter is really full.
When vacuuming during the early days of the SLAM the water running through the pump was quite green and I did vacuum up quite a bit of white flakes (calcium?). Probably a pump basket worth.
I'm betting the flakes came from my previous attempt to open the pool where, at the advice of then local pool store, I burned through ~3Kg of Cal-Hypo about a week trying to get rid of the algae before finding TFP and getting a proper test kit.
I think I've been pretty thorough reading through existing forum posts, understanding the tests (including Taylor K-2006 manual), and read through the Pool School posts here. We really haven't been able to enjoy the pool at all this year and I'm starting to run out of ideas. Maybe someone more experienced than me sees a glaring issue or has advice on the best course of action?
Otherwise I think my options are one of the following:
- Raise FC to try a mustard algae shock
- Drain the pool down to the return and deep clean the sand filter.
- Drain the pool completely, pressure wash liner, re-fill. The pool is so old I'd be worried about the liner shrinking/drying out and breaking it. If it did work, I'd probably call it for the season and try again next summer.
- Ditch the pool and think about getting in line to get a new one in a few years (current wait time is ~2-3 years).
- The pool is getting long in the tooth (~15 years) with some uneven pits in the floor of the pool and liner slipping on the sides in some places.