Green pool again

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
Hello TFP community.
2 month ago my water pool was green, I did the SLAM process with success (OCLT passed)
I noticed green on the wall came back more often, in less days, and more often I need to add muratic to balance my ph
My water began to turn slowly green, even with daily maintenance and chemical checking. After few days, I figured it out the spider gasket was damaged again, so probably bad quality.
So this time I ordered the full "key, cover and handle assembly" for my filter. It took the weekend to come. But the water during this time turned completely green.
So I began the SLAM process. It was Monday. And since then no improvement at all...
Desperate, and believing my filter is still wrong, I called a pool guy yestesday, who have good reputation on the neighborhood. He checked the filter and put DE on the skimmer to see if goes out through the buses. Nothing goes out. So apparently it's good, the filter is doing his job, with the DE, it raised the pressure. We backwashed it. And he put an algeacide on it (call Algatec).
I continued the SLAM process.
The next day, today, still no improvement.
So should I be more patient?
Thank you for your help.
Here my PoolMath link PoolMath Logs
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
36,116
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
The last CYA test I see in your logs was 30 ppm. That is OK for the SLAM Process, but not for normal maintenance. You need at least 50 ppm CYA in your water here.

The algaecide has all ready been consumed by the chlorine. A waste of money.
Maintain your FC at 12 ppm every two hours or so.
 

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
The last CYA test I see in your logs was 30 ppm. That is OK for the SLAM Process, but not for normal maintenance. You need at least 50 ppm CYA in your water here.

The algaecide has all ready been consumed by the chlorine. A waste of money.
Maintain your FC at 12 ppm every two hours or so.
Ok, one more pool guy useless, I was worry about that...
Ok understood for the CYA, I believe the less the better and 30 was enough

So you advice me to just be patient? no to try to investigate on the filter?

Thank you for your advises
 

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
The last CYA test I see in your logs was 30 ppm. That is OK for the SLAM Process, but not for normal maintenance. You need at least 50 ppm CYA in your water here.

The algaecide has all ready been consumed by the chlorine. A waste of money.
Maintain your FC at 12 ppm every two hours or so.
Shoud I not have seeing some improvement in 72 hours?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
36,116
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Filter does not solve or create algae. It is needed to filter out the dead algae.
Why do you think you have an issue with the filter?

Less CYA is good to a point, but with our UV impact, I suspect your FC is dropping rapidly mid day.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
36,116
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Shoud I not have seeing some improvement in 72 hours?
Are you following the SLAM Process? Testing FC and adding chlorine every couple hours? Running pump 24 hours per day? Brushing and vacuuming pool once a day, at least?
 

JJ_Tex

Gold Supporter
Bronze Supporter
Jul 17, 2019
2,293
Prosper, TX (DFW)
Pool Size
13000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
And looking through your logs, you spent all of June, July, and part of August at a very low FC level. Once you finish the SLAM, make sure you are keeping your FC at the correct levels (see my signature if you need) to keep the algae away for good.
 

CrystalRiver

Well-known member
Jun 19, 2020
449
Massachusetts
Looking at your logs, I see you testing and adjusting pH during your SLAM. Leave it alone. Your pH readings are not accurate with the elevated chlorine levels.

If your FC happens to drop below 10, perhaps overnight, then you can test your pH. Otherwise, it's not accurate.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
15,510
Evans, Georgia
Ok, one more pool guy useless, I was worry about that...
Ok understood for the CYA, I believe the less the better and 30 was enough

So you advice me to just be patient? no to try to investigate on the filter?

Thank you for your advises

Thomas, algae is a CHEMISTRY problem. Filtering is a MECHANICAL problem. If you have algae your chemistry is off- usually either too low FC or too high CYA.
BUT.....you live in the very hot west.... more sun and UV than most of us... so you actually need a skosh more CYA to protect your FC than most of us East of you. And when you have higher CYA you need to continue to follow the FC/CYA chart for guidance on how high your FC should be.

See---> FC/CYA Chart <----- See

I hope this explains it and helps clear up any confusion.

Maddie
 

Enjoying this content?

Support TFP with a donation.

Give Support

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
And looking through your logs, you spent all of June, July, and part of August at a very low FC level. Once you finish the SLAM, make sure you are keeping your FC at the correct levels (see my signature if you need) to keep the algae away for good.
Usually, I do my test at the end of the day and just after put chlorine on it, according my tests
I am guessing the chlorine get consumed by the sun during the day, in the average I put 48 oz every day.
 

JJ_Tex

Gold Supporter
Bronze Supporter
Jul 17, 2019
2,293
Prosper, TX (DFW)
Pool Size
13000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I'm guessing that is what happened, but the minimum is still the minimum and will allow algae to grow if the FC dips below there. For a CYA of 30, the minimum is 2, target is 4-6. I would make sure and bring it up to at least 6 when you add on a daily basis, but there is no harm in bringing it up to 7 or 8 if you are seeing a lot of burn off during the day.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
36,116
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
in the average I put 48 oz every day.
That is 1.2 ppm FC per day. In the summer. My pool consumes 4.5 ppm FC per day, at 70 ppm CYA.

Just a comparison.
 

CrystalRiver

Well-known member
Jun 19, 2020
449
Massachusetts
An FC of 0.4 or 0.0 is too too low at any point in time. That's where your algae is coming from.

Either you aren't adding enough chlorine to get your levels up to where they need to be, or it's getting burned off too quickly. If it's burning off that fast, you need to raise the CYA or dose multiple times a day. But first, finish the SLAM, and then figure out if your chlorine perhaps isn't as strong as you think, or you were targeting too low, or if it's being consumed that quickly.
 

JJ_Tex

Gold Supporter
Bronze Supporter
Jul 17, 2019
2,293
Prosper, TX (DFW)
Pool Size
13000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Also, what strength of liquid chlorine are you using. 48oz is not a lot.

Never mind - Mknauss beat me to it.
 

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
Thomas, algae is a CHEMISTRY problem. Filtering is a MECHANICAL problem. If you have algae your chemistry is off- usually either too low FC or too high CYA.
BUT.....you live in the very hot west.... more sun and UV than most of us... so you actually need a skosh more CYA to protect your FC than most of us East of you. And when you have higher CYA you need to continue to follow the FC/CYA chart for guidance on how high your FC should be.

See---> FC/CYA Chart <----- See

I hope this explains it and helps clear up any confusion.

Maddie
Yes but the filter not removing the dead algae (if the filter is an issue) will keep my pool green, is it not? But reading your answer, the filter doesn't seem to be the issue here...
So I will continue my SLAM, and will see. But no seeing any improvement, doesn't help to believe I was in the good way... I will be more patient.
You right about the CYA because I felt I put a lot of chlorine ever day (average 48oz) and still doesn't seem enough?
Ok I have a 30k gallons pool, but no pool party (because the covid), no kid peeing on the pool, no dog... just 2 peoples (and a lot of UV, ok).
 

Thomas Vegas

Well-known member
Mar 5, 2019
59
Las Vegas
An FC of 0.4 or 0.0 is too too low at any point in time. That's where your algae is coming from.

Either you aren't adding enough chlorine to get your levels up to where they need to be, or it's getting burned off too quickly. If it's burning off that fast, you need to raise the CYA or dose multiple times a day. But first, finish the SLAM, and then figure out if your chlorine perhaps isn't as strong as you think, or you were targeting too low, or if it's being consumed that quickly.
OK understood.
For the CYA, I believe the lower the better... 50 seems to be the correct amount.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
15,510
Evans, Georgia
Algae that dies will land on the floor and look like silt or dirt that floofs away if you get near it. A S-L-O-W vac to waste will help get it OUT of there.

Brushing daily keeps it stirred up in circulation so that the filter will capture it, as well as the brushing disrupting any biofilm which can be hiding algae below.

Maddie
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.