Struggling with Algae

[mknauss]

I never removed it but opened up a corner to check chemicals daily.

This implies you were not brushing, using a pool vac, etc. Does the algae return if you do those things on a weekly or more often basis?

 

[SecoSteve]

You mentioned that you have a boat. Do you swim in the ocean or other non pool water, and then swim in the pool with the same bathing suit that you were using in the ocean? I've read that could bring contaminants into the pool.

Also, could you post some pictures of your pool, so show places where algae could be hiding?

 

[Ksbguy]

Mustard algae tends to grow on the walls and floor of the pool on the shaded side.

Is that what you see?

There is zero shade here, pool is in the sun 99% of days. I see it mainly on shallow and deep end cross the width from bottom of the wall to about 2' out. Don't see much on the walls, also get it on the sun shelf that has a couple of bubbler's in it.

I just found algae in salt my chlorinator (where you put the tabs) that I don't use. It's on so water was flowing and I'm not sure why algae would grow in there with chlorinated water flowing through.

FC levels still holding at 16ppm. It's raining here today so no sunlight to burn it off...

 

[Ksbguy]

You mentioned that you have a boat. Do you swim in the ocean or other non pool water, and then swim in the pool with the same bathing suit that you were using in the ocean? I've read that could bring contaminants into the pool.

Also, could you post some pictures of your pool, so show places where algae could be hiding?

No, never do that and always use an outdoor shower before getting in the pool. I posted a couple of pictures. There's no ladder or anything other then a sun shelf with bubblers.

 

[Ksbguy]

This implies you were not brushing, using a pool vac, etc. Does the algae return if you do those things on a weekly or more often basis?

I did remove it quickly for an hour or so to brush and vacuum when the cover stayed on but didn't take the cover off for a day and use the pool during that time. It wasn't weekly, was every couple weeks. I saw a little bit of algae the first time and thought it was just because I hadn't brushed it but two weeks later it was a nice surprise.

The cover has been off for months now with regular brushing and vacuuming. The brushing has been every 3 - 4 days now to keep the algae from getting worse.

When I cleaned my filter last week it had a lot of green algae on it.

 

[SecoSteve]

No, never do that and always use an outdoor shower before getting in the pool. I posted a couple of pictures. There's no ladder or anything other then a sun shelf with bubblers.

Then you gotta chalk it up to the solar cover being on too long and maybe your FC level dropped too low. Are you now algae free?

 

[Mdragger88]

Round up the usual suspects-
Solar Cover
Nook’s & crannies (high fc alone doesn’t do the trick - gotta scrub those crannies!)

 

[Ksbguy]

Then you gotta chalk it up to the solar cover being on too long and maybe your FC level dropped too low. Are you now algae free?

I actually maintained the FC with the cover on. No, the algae keeps coming back. It's very minor but it's the gift that keeps on giving.

 

[Ksbguy]

Round up the usual suspects-
Solar Cover
Nook’s & crannies (high fc alone doesn’t do the trick - gotta scrub those crannies!)

Brushed every corner and crannie I could find, we will see!

 

[Ksbguy]

Still curious about this though. If you see a little algae, I mean like a little spot on the bottom in one area do you just brush and move on or does that mean you have to SLAM? I'm not talking about cloudy water or a lot of visible algae I'm talking about a very small amount, you brush it and can see a green dust get dispersed into the water, the next day it's not there and crystal clear but a week later it's back again.

 

[Mdragger88]

Still curious about this though. If you see a little algae, I mean like a little spot on the bottom in one area do you just brush and move on or does that mean you have to SLAM? I'm not talking about cloudy water or a lot of visible algae I'm talking about a very small amount, you brush it and can see a green dust get dispersed into the water, the next day it's not there and crystal clear but a week later it's back again.

Any visible algae = slam time.
You either have algae or you don’t. It reoccurs because it either hasn’t been fully eradicated or fc went too low at some point after it was eradicated.
If you see it in the same exact spot every time it may need investigation, perhaps that area isn’t getting the circulation of the rest of the pool & fc dips too low there. In which case, slam whilst also making changes to correct the situation if possible. If not possible to change flow circumstances then you would want to go with higher maintenance fc levels so that particular spot doesn’t dip too low.
There’s really no upside to playing kissy face with minimum.
Run fc a little higher than you have been & know you’re covered (after completing slam)

 

[Ksbguy]

Any visible algae = slam time.
You either have algae or you don’t. It reoccurs because it either hasn’t been fully eradicated or fc went too low at some point after it was eradicated.
If you see it in the same exact spot every time it may need investigation, perhaps that area isn’t getting the circulation of the rest of the pool & fc dips too low there. In which case, slam whilst also making changes to correct the situation if possible. If not possible to change flow circumstances then you would want to go with higher maintenance fc levels so that particular spot doesn’t dip too low.
There’s really no upside to playing kissy face with minimum.
Run fc a little higher than you have been & know you’re covered (after completing slam)

I will try that thank you for your help.

 

[Ksbguy]

I see FC levels for SWG have a larger range and are lower than LC levels. Why is that, because of the salt in the water?

 

[PoolStored]

I see FC levels for SWG have a larger range and are lower than LC levels. Why is that, because of the salt in the water?

Basically, with SWGs you have a lower FC level being produced & maintained continuously through the 24 hr period as opposed to the one-time liquid dumping. That along with the production of chlorine gas (versus liquid) has shown that a higher CYA protects the chlorine gas better and helps to maintain a more consistent/reliable FC level.

 

[Ksbguy]

I did the SLAM and beyond SLAM. Went an additional two days with FC levels 16-18 with a CYA of 40. 0 ppm drop over night, scrubbed every nick and cranny, there wasn't any visible algae anywhere. Since then I've been maintaining CL 5 - 7 as recommended for CYA of 40 and I'm starting to see the algae come back when brushing weekly. Is it expected to have some algae when brushing weekly or should I be seeing none. Concerned about constant SLAM on a pool with new plaster. Thanks.

 

[Mdragger88]

When you ended slam there was no algae, dead or alive, correct?

 

[DrewLG]

I've been maintaining CL 5 - 7 as recommended for CYA of 40 and I'm starting to see the algae come back when brushing weekly. Is it expected to have some algae when brushing weekly or should I be seeing none..

You should be seeing none.

Ugh, this must be frustrating. But it feels like you're close.

Algae will not spontaneously bloom in water with 40ppm CYA and 5-7ppm FC, so I can only think of a few things that might be happening:

1. FC is lower, at least in some places and/or at some times, than 4ppm.
   If the algae is consistently appearing in the same places, try performing FC tests with water from those areas/depths, at worst-case times of day: early afternoon, 11 hours and 55 minutes after the pump turns off, etc.
   
   
2. CYA is much much higher than 40ppm.
   If this were the only cause for the algae bloom, it would have to be WAY higher -- like 100+. Very unlikely.
   
   
3. An active algae colony was introduced after the SLAM.
   Your earlier posts indicated that the cover was a likely source of algae. You said you maintained the SLAM FC level with the cover on -- so floating, not weighted and submerged, right? Have you used the cover since completing the SLAM?
   
   
4. The SLAM did not kill all the algae.
   You earlier discovered some algae in a disused tab chlorinator. Is it possible that algae is hidden in other parts of your plumbing? Maybe in other unused portions (e.g. an old booster pump that's been replaced by a robot), in the fill hose or autofill/overflow pipes, under drain covers, behind weir doors, inside light niches, etc.

 

[HermanTX]

I did the SLAM and beyond SLAM. Went an additional two days with FC levels 16-18 with a CYA of 40. 0 ppm drop over night, scrubbed every nick and cranny, there wasn't any visible algae anywhere. Since then I've been maintaining CL 5 - 7 as recommended for CYA of 40 and I'm starting to see the algae come back when brushing weekly. Is it expected to have some algae when brushing weekly or should I be seeing none. Concerned about constant SLAM on a pool with new plaster. Thanks.

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What type of filter do you have? After the SLAM did you backwash it or clean it as it may have trapped some live algae?
After a SLAM, you might consider keeping your FC on the high side of the range for your CYA level. Also, it is good to reverify your CYA level before letting the FC drop from the SLAM levels.

 

[Ksbguy]

When you ended slam there was no algae, dead or alive, correct?

Correct, zero.

 

[Ksbguy]

You should be seeing none.

Ugh, this must be frustrating. But it feels like you're close.

Algae will not spontaneously bloom in water with 40ppm CYA and 5-7ppm FC, so I can only think of a few things that might be happening:

1. FC is lower, at least in some places and/or at some times, than 4ppm.
   If the algae is consistently appearing in the same places, try performing FC tests with water from those areas/depths, at worst-case times of day: early afternoon, 11 hours and 55 minutes after the pump turns off, etc.
   Good idea, I have not tried this. It's first visible on shallow end and deep end only.
2. CYA is much much higher than 40ppm.
   If this were the only cause for the algae bloom, it would have to be WAY higher -- like 100+. Very unlikely.
   I checked this with tf pro kit I have and two pool stores. I get 40, pool stores say 40 and 43.
3. An active algae colony was introduced after the SLAM.
   Your earlier posts indicated that the cover was a likely source of algae. You said you maintained the SLAM FC level with the cover on -- so floating, not weighted and submerged, right? Have you used the cover since completing the SLAM?
   No cover for months.
4. The SLAM did not kill all the algae.
   You earlier discovered some algae in a disused tab chlorinator. Is it possible that algae is hidden in other parts of your plumbing? Maybe in other unused portions (e.g. an old booster pump that's been replaced by a robot), in the fill hose or autofill/overflow pipes, under drain covers, behind weir doors, inside light niches, etc. This was before finishing SLAM. I overdid the SLAM by days. Perfectly clear water and not a trace of algae anywhere. Pipes would all have had shock levels through them, pool is brand new. I backwashed the filter twice, right after the SLAM was done and two days later again.

Thank you and see comments above in blue. What is the purpose of brushing plaster if nothing should be on it? Aside from brushing a new pool plaster during curing?