Hi All,
As mentioned in my intro, I have a black algae problem. It's the reason I'm here. After months of reading and hearing different things to try, this is my last resort. Fingers crossed.
Background:
The pool was built over the first 9 months of 2022. It was officially filled with water on September 1st. Within a week I found several black spots on the stairs. After some scrubbing, the black spots lessened a little, but revealed a hard center, like a raised pebble. It's hard to say what could have gone wrong in that first 7-10 days, I have a few working theories for another time.
The only way I've been able to remove the black algae is by heavily dosing in acid OR using an ice pick. The pick can crush the algae sometimes. I have noticed that when the pool has had a recent shock, the algae is easier to remove, but I've only been able to put a dent in the population as it has spread to the entire pool. Generally, I scrub with a metal brush, and now that the weather has warmed, I have been getting in again to scrape the algae with an ice pick.
Present Pool Conditions:
Salt Water Pool running 16 hours/day at 15% Chlorinator (recently lowered because chlorine was very high, it has been in the 7-11 ppm range for several weeks now).
FC: 10.5ppm, CC: 0.5ppm, CYA: 70-90* pH: 8.0, verified with Taylor K-2006C
TA: 135ppm, CH: 240ppm verified by In-Store Pool Test (will verify with test kit tomorrow, ran out of daylight today)
Filter is original and pretty gunked up, I have the replacement catridge ready, just didn't know if I should deploy now or after treatment.
Initial Plan:
I've read the literature on this site and several others, I was originally going to try copper, but after finding TFP, I wanted to give this a try first.
First, on the CYA test, how accurate can this be with the black dot and cloudy liquid test? Depending on the lighting conditions, you can see the black dot better or worse. I first started to lose sight of the black dot around 90-100ppm, but could still faintly make it out up to around 70ppm, that why I listed 70-90ppm as the range. I understand this is very high and from the calculator it means the high end of the "Maintain" Range is between 10-12 ppm FC, which is roughly where I am at. The SLAM/Shock level would be 28-35ppm.
Second, understood the pH is too high. Some acid was added last week, but once receiving the test kit, I have a better idea on how much acid to add and will get the pH down to 7.4 before proceeding.
That said, once CYA and pH issues above are resolved, will move forward with below plan of continuous treatment until BA disappears:
* Run pool 24 hours/day
* Brush pool several times a day with steel brush (I've already been using one fairly often)
* Maintain FC level between 12-28. Would 15 ppm be alright? Can FC be added via the SWG rather than liquid chlorine? Since I am already at 10.5ppm FC, getting into the 14-18 range would not be difficult by turning up the SWG%, I believe it even has a "shock" setting.
* Monitor/Maintain all other parameters.
A few further questions:
1. At what point do I risk staining the pool with excessive chlorine?
2. As mentioned above, when should I swap in the new filter?
3. Should I do a water exchange with fresh water to get the CYA down? Or would this create more issues as I have to rebalance several other parameters?
Any advice or feedback on the above plan would be hugely appreciated. I have owned a pool for about 5 years now, but this is the first pool I had built new. With my old pool, I never had any issues with algae, just plumbing leaks and equipment issues.
Thank you,
Mike
As mentioned in my intro, I have a black algae problem. It's the reason I'm here. After months of reading and hearing different things to try, this is my last resort. Fingers crossed.
Background:
The pool was built over the first 9 months of 2022. It was officially filled with water on September 1st. Within a week I found several black spots on the stairs. After some scrubbing, the black spots lessened a little, but revealed a hard center, like a raised pebble. It's hard to say what could have gone wrong in that first 7-10 days, I have a few working theories for another time.
The only way I've been able to remove the black algae is by heavily dosing in acid OR using an ice pick. The pick can crush the algae sometimes. I have noticed that when the pool has had a recent shock, the algae is easier to remove, but I've only been able to put a dent in the population as it has spread to the entire pool. Generally, I scrub with a metal brush, and now that the weather has warmed, I have been getting in again to scrape the algae with an ice pick.
Present Pool Conditions:
Salt Water Pool running 16 hours/day at 15% Chlorinator (recently lowered because chlorine was very high, it has been in the 7-11 ppm range for several weeks now).
FC: 10.5ppm, CC: 0.5ppm, CYA: 70-90* pH: 8.0, verified with Taylor K-2006C
TA: 135ppm, CH: 240ppm verified by In-Store Pool Test (will verify with test kit tomorrow, ran out of daylight today)
Filter is original and pretty gunked up, I have the replacement catridge ready, just didn't know if I should deploy now or after treatment.
Initial Plan:
I've read the literature on this site and several others, I was originally going to try copper, but after finding TFP, I wanted to give this a try first.
First, on the CYA test, how accurate can this be with the black dot and cloudy liquid test? Depending on the lighting conditions, you can see the black dot better or worse. I first started to lose sight of the black dot around 90-100ppm, but could still faintly make it out up to around 70ppm, that why I listed 70-90ppm as the range. I understand this is very high and from the calculator it means the high end of the "Maintain" Range is between 10-12 ppm FC, which is roughly where I am at. The SLAM/Shock level would be 28-35ppm.
Second, understood the pH is too high. Some acid was added last week, but once receiving the test kit, I have a better idea on how much acid to add and will get the pH down to 7.4 before proceeding.
That said, once CYA and pH issues above are resolved, will move forward with below plan of continuous treatment until BA disappears:
* Run pool 24 hours/day
* Brush pool several times a day with steel brush (I've already been using one fairly often)
* Maintain FC level between 12-28. Would 15 ppm be alright? Can FC be added via the SWG rather than liquid chlorine? Since I am already at 10.5ppm FC, getting into the 14-18 range would not be difficult by turning up the SWG%, I believe it even has a "shock" setting.
* Monitor/Maintain all other parameters.
A few further questions:
1. At what point do I risk staining the pool with excessive chlorine?
2. As mentioned above, when should I swap in the new filter?
3. Should I do a water exchange with fresh water to get the CYA down? Or would this create more issues as I have to rebalance several other parameters?
Any advice or feedback on the above plan would be hugely appreciated. I have owned a pool for about 5 years now, but this is the first pool I had built new. With my old pool, I never had any issues with algae, just plumbing leaks and equipment issues.
Thank you,
Mike
