I am a second year pool owner, and with a lot of help from this forum the first two years have largely been a success. I use the TFP method, though perhaps a little loosely at times. No sig yet but rough pool setup:
~30k gallon IG gunite pool, circa 2004
Single speed pump, DE filter
Located in NH, so close pool in winter
Have proper test tik
Using the TFP methods (liquid chlorine) I have maintained the pool in a largely algae-free fashion, after a few early stumbles. Last year the pool opening went very well, was a green mess when I started but largely clean and clear ~5 days later. Ran filter 24/7, backwashed often, removed leaves with net, brushed, and SLAMed. Noticed when we opened it this year that my tile line was really starting to deteriorate (three tiles were down when we bought the house, none fell last winter, this winter we probably lost 10-15 so tile repair is now on the list). But other than that I started the season feeling good, perhaps a little cocky.
Well, the opening this year did not go well. As best as I can recall I largely followed the same steps. Pool was opened by pool company Wednesday (de-winterized). I wasn't out there and they added "non-chlorine shock" and algecide, perhaps my first mistake. I like the TFP philosophy of tightly controlling what goes in my pool, but that one slipped by. I let the filter (24/7, frequent backwashes at first, then as needed per PSI) and their chemicals work for about 24hrs and then started testing and removing leaves, FC was zero so I started adding liquid choline. I knew from last year my CYA was probably very low but I figured i could deal with that once the pool had cleared up a bit (second mistake). I hit it hard with liquid choline, though I was a little loose at first and just added rough slam levels from prior experience, like 2.5-3 gallons every 12hrs or so. That is usually enough to bring my FC up to 12-15. I tested and it was falling fast, particularly during the day, but I just kept adding chlorine, I will admit without much precision. I thought once the water cleared up I would get more scientific. This went on for about 3 days, then over the weekend it got very hot up here. I lost chlorine fast and did read 0 a couple times over the weekend. That worried me, but the water was improving, clarity-wise, and I did a CC test and it read <0.5ppm so I felt like I had dodged the algae bullet.
By Sunday, the water was pretty clear and I realized something had gone wrong. The pool floor in general had looked a little dingier than last year, with brighter outlines where leaves had sat on the bottom. But I assumed that would either get swept up by the robot or fade withe the chlorine. By Sunday it was clear those dingy areas were not fading quickly, and even worse a large amount of fairly nasty stains on the pool floor had developed. They seemed to get worse over the weekend, making me think that I did not dodge the algae bullet after all.
So, on Sunday I got religion. Restocked liquid chlorine and added 8bls of CYA (not all at once), now reading 40ppm. Pool has been at SLAM levels ever since. The stains may be fading a bit. I have brushed them a lot with both steel and nylon brushes. There are honestly so many that I have prioritized a few spots for heavier brushing and it may be making a little difference. But I am a frustrated pool owner. It seems glaringly obvious in hindsight that I should have gotten CYA in the pool much sooner to protect my chlorine, and been more diligent about not letting it hit zero. I also recall brushing the top two steps a little earlier in the process than the bottom step and floor, and indeed the top two steps looks a lot better.
But I am still not sure exactly what types of stains these are, what specifically in my process allowed them to happen, and if SLAM/brushing is the right remedy. I will do an OCLT tonight, I didn't lose much last night, although I did loose a good amount of FC during the day today. My last CC test again read <0.5ppm. My other numbers are ph 7.4, TA 80, CH 140 (so I'll get some calcium hardener in there). I don't see any traditional green algae that I had a few time in the past. I am not sure if these stains are black algae, yellow, leaf stains, or something else. I do top off pool with well water, so could have some iron (but that was true last year as well). Also possible there was copper in whatever the pool store guys used (but it seems to be better a little better with high FC, not worse).
Anyway, here is the damage. The first pic was Sunday, the second was 48hrs into the legit slam phase. Any advice, in terms of both remedy and future prevention, would be greatly appreciated. And again, many thanks to the forum as I have found
~30k gallon IG gunite pool, circa 2004
Single speed pump, DE filter
Located in NH, so close pool in winter
Have proper test tik
Using the TFP methods (liquid chlorine) I have maintained the pool in a largely algae-free fashion, after a few early stumbles. Last year the pool opening went very well, was a green mess when I started but largely clean and clear ~5 days later. Ran filter 24/7, backwashed often, removed leaves with net, brushed, and SLAMed. Noticed when we opened it this year that my tile line was really starting to deteriorate (three tiles were down when we bought the house, none fell last winter, this winter we probably lost 10-15 so tile repair is now on the list). But other than that I started the season feeling good, perhaps a little cocky.
Well, the opening this year did not go well. As best as I can recall I largely followed the same steps. Pool was opened by pool company Wednesday (de-winterized). I wasn't out there and they added "non-chlorine shock" and algecide, perhaps my first mistake. I like the TFP philosophy of tightly controlling what goes in my pool, but that one slipped by. I let the filter (24/7, frequent backwashes at first, then as needed per PSI) and their chemicals work for about 24hrs and then started testing and removing leaves, FC was zero so I started adding liquid choline. I knew from last year my CYA was probably very low but I figured i could deal with that once the pool had cleared up a bit (second mistake). I hit it hard with liquid choline, though I was a little loose at first and just added rough slam levels from prior experience, like 2.5-3 gallons every 12hrs or so. That is usually enough to bring my FC up to 12-15. I tested and it was falling fast, particularly during the day, but I just kept adding chlorine, I will admit without much precision. I thought once the water cleared up I would get more scientific. This went on for about 3 days, then over the weekend it got very hot up here. I lost chlorine fast and did read 0 a couple times over the weekend. That worried me, but the water was improving, clarity-wise, and I did a CC test and it read <0.5ppm so I felt like I had dodged the algae bullet.
By Sunday, the water was pretty clear and I realized something had gone wrong. The pool floor in general had looked a little dingier than last year, with brighter outlines where leaves had sat on the bottom. But I assumed that would either get swept up by the robot or fade withe the chlorine. By Sunday it was clear those dingy areas were not fading quickly, and even worse a large amount of fairly nasty stains on the pool floor had developed. They seemed to get worse over the weekend, making me think that I did not dodge the algae bullet after all.
So, on Sunday I got religion. Restocked liquid chlorine and added 8bls of CYA (not all at once), now reading 40ppm. Pool has been at SLAM levels ever since. The stains may be fading a bit. I have brushed them a lot with both steel and nylon brushes. There are honestly so many that I have prioritized a few spots for heavier brushing and it may be making a little difference. But I am a frustrated pool owner. It seems glaringly obvious in hindsight that I should have gotten CYA in the pool much sooner to protect my chlorine, and been more diligent about not letting it hit zero. I also recall brushing the top two steps a little earlier in the process than the bottom step and floor, and indeed the top two steps looks a lot better.
But I am still not sure exactly what types of stains these are, what specifically in my process allowed them to happen, and if SLAM/brushing is the right remedy. I will do an OCLT tonight, I didn't lose much last night, although I did loose a good amount of FC during the day today. My last CC test again read <0.5ppm. My other numbers are ph 7.4, TA 80, CH 140 (so I'll get some calcium hardener in there). I don't see any traditional green algae that I had a few time in the past. I am not sure if these stains are black algae, yellow, leaf stains, or something else. I do top off pool with well water, so could have some iron (but that was true last year as well). Also possible there was copper in whatever the pool store guys used (but it seems to be better a little better with high FC, not worse).
Anyway, here is the damage. The first pic was Sunday, the second was 48hrs into the legit slam phase. Any advice, in terms of both remedy and future prevention, would be greatly appreciated. And again, many thanks to the forum as I have found
