Algae or Another Big Problem?

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osensnolf

0
Sep 10, 2015
29
NC
This is my 2nd year as a pool owner. My first year was great with only a couple issues of yellow mustard algae that I was able to quickly correct.

This year has been a pain.

Every few days the bottom of the pool starts to look a little dingy. Guest would not notice but enough that I know. If I brush the bottom a dark cloud of matter appears.

I have vacuumed/drained the surface, shocked many times to 20PPM. Everything will look great for a few days and then it is back.

The water is balanced. I’ve used a digital tester and Taylor test kit. Right now my CL is at 9 since I added more yesterday.

It impacts the entire pool – almost evenly with the corners more noticeable.

Thoughts

16x32 IG Vinyl, 17k Gallons
 
That sure sounds like a chemistry problem. Which Taylor test kit do you have? Does it have the FAS-DPD powder? What are you using to "shock" this pool- as you may have read we don't cure algae by tossing in a product one or twice labeled "shock" but we kill it with a SLAM Process procedure.

Please give us:
FC
CC
pH
TA
CH
CYA
 
I have the Taylor K-2006

To shock (bring up chlorine level), I am using HTH Shock-and-Swim as well as Kem Tek liquid chlorine (not at the same time - just rotating to see which works the best).

FC: 0
CL: 9.4
ph: 7.3
alk: 90
CYA: 30 (the test requires that I fill the container until I cannot see the black dot. I have great vision, does that alter the rating since I may be able to see it better than someone else?)

I let the pump run for a minimum of 8 hours with daily averages of 10 hours and sometimes all night after a treatment.
 
Well, using it and trying to dose it out for a SLAM is difficult, excess calcium can contribute to scale formation and sometimes makes water cloudy. Trichlor and Dichlor also are acidic.

Fresh plain liquid chlorine is the best thing to use.
 
osensnolf said:
I have the Taylor K-2006

To shock (bring up chlorine level), I am using HTH Shock-and-Swim as well as Kem Tek liquid chlorine (not at the same time - just rotating to see which works the best).

FC: 0
CL: 9.4
ph: 7.3
alk: 90
CYA: 30 (the test requires that I fill the container until I cannot see the black dot. I have great vision, does that alter the rating since I may be able to see it better than someone else?)

I let the pump run for a minimum of 8 hours with daily averages of 10 hours and sometimes all night after a treatment.
Click to expand...
Your test results are confusing..... FC=0? What is CL?

Pool School - ABCs of Pool Water Chemistry

How did you get a PH of 7.3? My Taylor K-2006 PH scale is 7.0, 7.2, 7.4, 7.6, 7.8, 8.0

Was the PH result between colors?

Please post a complete set of test results including:
FC
CC
PH
TA
CH
CYA

Dom
 
The water itself is clear as all particles are at the bottom of the pool. It's not even bad enough that a camera would pick it up but pool guys would visually notice in person. If I do not do anything about it, tomorrow it will look worse and the steps will have a yellowish tent to it - similar to how things looks with Augusta pines drop pollen on your car.

I can start using chlorine.

Here are pictures if this helps.
View attachment 50770
View attachment 50771
 

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I will SLAM it and see how that goes and only use liquid chlorine from now on.

Is there another way to test CYA?

My chlorine level has been above 8 for over a week and still the problem is getting worse. That makes me think CYA is higher than the test shows in which the chlorine level would need to be higher than the SLAM chart... right?

Thanks
 
osensnolf said:
I will SLAM it and see how that goes and only use liquid chlorine from now on.

Is there another way to test CYA?

My chlorine level has been above 8 for over a week and still the problem is getting worse. That makes me think CYA is higher than the test shows in which the chlorine level would need to be higher than the SLAM chart... right?

Thanks
Click to expand...

Previously you said you thought your CYA was 30. IF it were 30, your SLAM level is 12 which you have to *maintain* until the pool is clear, the OCLT is less than 1 and your CCs are 0.5 or less.

[FC/CYA][/FC/CYA]
SLAM Process
 
osensnolf said:
I will SLAM it and see how that goes and only use liquid chlorine from now on.

Is there another way to test CYA?

My chlorine level has been above 8 for over a week and still the problem is getting worse. That makes me think CYA is higher than the test shows in which the chlorine level would need to be higher than the SLAM chart... right?

Thanks
Click to expand...
The reason the situation is getting worse is that you are not killing the algae. We have recommended more than once that the pool needs a SLAM, and this is the procedure:

http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

If your CYA is 30, your shock level for the SLAM is 12ppm, not "above 8". Keep the pool at a FC of 12ppm for the duration of the SLAM. It's OK to dose a couple of ppm above the 12, just don't go overboard as it will just waste chlorine as well as be harsh on your pool. If you see that you are losing 3ppm of FC between tests, target 15-16ppm so FC is 12ppm or better at your next test.

Unfortunately there is no other cost effective and reliable way to check CYA that I know of, and it is the test we all struggle with at some point. Remember, you can always put the sample back in the mixing bottle, go to a different spot in the yard and test again, repeat, etc until you have a comfortable result (practice, practice, practice). The most important part of the CYA test is to have as much indirect light as possible. Keep your back to the sun and check at waist level in your shadow, but there should be enough indirect sunlight to illuminate the tube. Make sure your hands do not block the sides of the view tube, I use two fingers to hold it right at the top so as not to block the sides. Always check outdoors on a bright sunny day, never when it's cloudy or overcast, or indoors.

The CYA test is important as it is directly related to your FC's effectiveness.

domct203 said:
Please post a complete set of test results including:
FC
CC
PH
TA
CH
CYA
Click to expand...

Dom
 
Last edited:
Hi.

As stated last night, I started the SLAM process yesterday. This morning CYA was around 30/35. (Do you keep dropping until you cannot see even a small amount of the dot?)

FC was at 12. I went ahead and added more to bring it closer to 16 as I know it will burn off in the hot sun today.

I'll maintain 12-16 four another night or two and then do the overnight test.

Thanks
 
osensnolf said:
Hi.

As stated last night, I started the SLAM process yesterday. This morning CYA was around 30/35. (Do you keep dropping until you cannot see even a small amount of the dot?)

FC was at 12. I went ahead and added more to bring it closer to 16 as I know it will burn off in the hot sun today.

I'll maintain 12-16 four another night or two and then do the overnight test.

Thanks
Click to expand...
Sorry for the confusion, your last post at 11:00pm last night said that you were 'above 8' and would SLAM, it just didn't say when... Didn't realize you started late last night.

How often are you able to test during the day?

Dom

osensnolf said:
I will SLAM it and see how that goes and only use liquid chlorine from now on.

Is there another way to test CYA?

My chlorine level has been above 8 for over a week and still the problem is getting worse. That makes me think CYA is higher than the test shows in which the chlorine level would need to be higher than the SLAM chart... right?

Thanks
Click to expand...
 
I did a complete brush this morning. My problem is that the water is clear. People see it and talk about how great it is and there is no hesitation for them to swim but as the owner and knowing how clear it can be, I am able to see the issue better.

I'm guessing I shouldn't swim while FC is 12-16? I guess I could google and see what the negative effects are but I'm sure others on here have real-world experience.
 
It is perfectly safe to swim with the FC up to shock level for your CYA level. That active chlorine level is actually less than you would find in a public pool with no stabilizer and an FC of one part per million.
 

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