Hi, would love to get a second opinion on black algae. We noticed algae growing in our pool. I was able to brush most of it off but there were a few stubborn spots. The pool company we use came out and shocked the pool and added algaecide. The spots are now gone within a couple of hours. I’m being told there is no way to completely get rid of it unless we drain the pool. They said we would need to keep the chlorine levels high because it is still in the water and will bloom back. I do not want to do this because I have little kids that swim and that’s why we did a saltwater pool to avoid high amounts of chlorine. Is there a way to fix this problem without draining the pool? Is there a way to test to confirm that it was actually black algae? It is a gunite pool.
Black Algae
- Thread starter khart0788
- Start date
-
- Tags
- black algae
- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
Welcome to TFP. Good to have you here 
First up, whether the pool is salt water or not, very nearly the same chlorine levels are needed to ensure bather safety. It's possible to keep chlorine levels marginally lower with a salt water chlorine generator (SWCG) because the pool is constantly dosed with chlorine (whenever pump and SWCG are running). The salt itself does not keep swimmers safe.
Yes on testing. Buy some trichlor pucks/tablets, and be 100% sure they do not contain copper. Scrub the area with a stainless steel brush. Then let a trichlor tablet rest on the darkened spot for two or three minutes, then move it aside and see if you see a difference. Repeat this a few times, placing it on the same spot. If there's a change, the stain is organic and can be eventually killed with brushing and chlorine.
If there's no change, then it may be a metal stain. Do you have any info about the algaecide the pool company has been adding? A lot of these use copper as the active ingredient, which is a no-no in pool care. Unfortunately pool stores and pool maintenance companies don't care about causing metal stains because they end up selling you more potions to get rid of the metal stains. Please never add copper to your pool, because copper above certain levels can lead to stains such as these.
Also have a look at this link... What is TFPC?
First up, whether the pool is salt water or not, very nearly the same chlorine levels are needed to ensure bather safety. It's possible to keep chlorine levels marginally lower with a salt water chlorine generator (SWCG) because the pool is constantly dosed with chlorine (whenever pump and SWCG are running). The salt itself does not keep swimmers safe.
Yes on testing. Buy some trichlor pucks/tablets, and be 100% sure they do not contain copper. Scrub the area with a stainless steel brush. Then let a trichlor tablet rest on the darkened spot for two or three minutes, then move it aside and see if you see a difference. Repeat this a few times, placing it on the same spot. If there's a change, the stain is organic and can be eventually killed with brushing and chlorine.
If there's no change, then it may be a metal stain. Do you have any info about the algaecide the pool company has been adding? A lot of these use copper as the active ingredient, which is a no-no in pool care. Unfortunately pool stores and pool maintenance companies don't care about causing metal stains because they end up selling you more potions to get rid of the metal stains. Please never add copper to your pool, because copper above certain levels can lead to stains such as these.
Also have a look at this link... What is TFPC?
Thanks for the response. That makes sense. I’m just concerned about having the chlorine on the high level with my little kids. There are no spots to test now. They disappeared within a couple of hours of them shocking the pool. I was able to brush the large spot off completely before they shocked it. I am just being told that it will always be in the water if we don’t drain the pool and I’m wondering if that is actually true? They also said I need to trash all of our floats and pool toys. I will try to get a picture of the algaecide and add it. I add 4oz of goodbye metal and algaecide weekly per their instructions.Welcome to TFP. Good to have you here
First up, whether the pool is salt water or not, very nearly the same chlorine levels are needed to ensure bather safety. It's possible to keep chlorine levels marginally lower with a salt water chlorine generator (SWCG) because the pool is constantly dosed with chlorine (whenever pump and SWCG are running). The salt itself does not keep swimmers safe.
Yes on testing. Buy some trichlor pucks/tablets, and be 100% sure they do not contain copper. Scrub the area with a stainless steel brush. Then let a trichlor tablet rest on the darkened spot for two or three minutes, then move it aside and see if you see a difference. Repeat this a few times, placing it on the same spot. If there's a change, the stain is organic and can be eventually killed with brushing and chlorine.
If there's no change, then it may be a metal stain. Do you have any info about the algaecide the pool company has been adding? A lot of these use copper as the active ingredient, which is a no-no in pool care. Unfortunately pool stores and pool maintenance companies don't care about causing metal stains because they end up selling you more potions to get rid of the metal stains. Please never add copper to your pool, because copper above certain levels can lead to stains such as these.
Also have a look at this link... What is TFPC?
- Jan 4, 2016
- 5,392
- Pool Size
- 44000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
TFPC uses CYA to buffer the chlorine, which holds the vast majority of chlorine in reserve and inactive. Therefore, a TFPC pool has less active chlorine than the water coming out of your tap (assuming you're on municipal water). Don't worry about the kids one bit when following TFPC. Our entire effort is to make swimming as safe as it can be for everyone using the pool. Worry when you don't have enough chlorine and your kids are subject to disease pressure from swimming with kids from other families. The presence of algae is our canary in the coal mine. When algae is successful, it's an indicator that sanitation may not be adequate for bather safety.
Glad the stains are gone. Definitely chase down copper and stop using it if that's happening now. If the 'goodbye metal' is a good sequestrant, you could exchange water and be rid of the metals risk, and then able to stop spending on sequestrant, if that's something you want.
Glad the stains are gone. Definitely chase down copper and stop using it if that's happening now. If the 'goodbye metal' is a good sequestrant, you could exchange water and be rid of the metals risk, and then able to stop spending on sequestrant, if that's something you want.
This little nugget from this and several older posts saved me a ton of time today! Had some green spots under leaves that sat overnight and I couldn't scrub them off. Threw a puck on there, and within 15 seconds they were gone. I do wonder what my pool company would've tried to sell me to get rid of them.