White powder - vinyl pool

[rjd1965]

Hi all,
I have a 35k gallon vinyl pool.
I have struggled with a white powder deposit on the bottom and in the corners.
I test my chems regularly and have them confirmed once a week at the pool store. This past week, they said it was very good with a slightly high CYA, but not actionable level.
Every so often I get this white powder. Water is crystal clear except for the deposits at the bottom. They brush into a cloud.
I shocked twice with cal hypo and when I do the water clouds up, then clears with more powder at the bottom.
I've vacuumed to my ctg filter, cleaned and even replaced the ctgs. This process reduces the powder and then I used an Algaecide 60 and it seemed completely gone.
Some time goes by and I see tiny powder remnants. I brush and check chems. And then twice now it spreads a lot on the floor.

I feel like I'm fighting and constantly killing algae and then it gets away from me. Or is it the calcium hypo dust? Or something else?

Water is so clear, but can't completely rid of this powder problem.

 

[cdadams1223]

Hi Robert and welcome to TFP! How are you testing your pool? You said you test it and then confirm with the pool store so I’m assuming you either have a test kit or strips. For starters, TFP does not rely on pool store testing or the use of “guess” strips. It is strongly recommended that you purchase a good, proven test kit. Test Kits Compared

As for the white stuff, could be dead algae. Algaecides are generally not recommended. If your free chlorine levels are within range according to your CYA levels, nothing should grow in your pool. Read further on this here to understand the relationship between CYA and FC.
FC/CYA Levels

Also, some excellent reading can be found here:
Pool Care Basics

Final advice, get a good kit (TF-Pro or K-2006C), run a full panel of tests, enter the results into
PoolMath, and post your results here.

 

[rjd1965]

Thank you for the reply. BTW, Ranger fan here.

I test with both strips (guess) and a kit. I get very different chlorine results between the two and, since the kit was left to me from the previous owner of the house, I was just googling to see if the reagents expire to see if that might explain the difference. The test strips always show I have significant free chlorine which matches the pool store, but the test kit shows a very light color so low cl.

My best bet is dead algae also, but can't explain why I can't rid the pool of it completely. And I'm very curious as to why the water does not get cloudy and why the powder is not yellow. When I go through the algae possibilities green clouds the water that's not what I have, yellow looks yellow, not white. And black algae is extremely rare in vinyl pools.
So I'm really wondering am I dealing with low levels of algae that bloom every once in a while that I have not completely gotten rid of? Or is it just deposits from the hypochlorate and putting in. Or something else. One clue for me is pool does cloud up when I shock it.

???

 

[Mdragger88]

What kit do you have?

 

[wireform]

Robert,
Before you start throwing pool store advised chems into the water get yourself the recommended test kit. I've been using the TF-100 and love it. The answers to your problem are easily remedied via good test results. Don't delay, order today from https://tftestkits.net as they ship very fast.

 

[cdadams1223]

Thank you for the reply. BTW, Ranger fan here.

I test with both strips (guess) and a kit. I get very different chlorine results between the two and, since the kit was left to me from the previous owner of the house, I was just googling to see if the reagents expire to see if that might explain the difference. The test strips always show I have significant free chlorine which matches the pool store, but the test kit shows a very light color so low cl.

My best bet is dead algae also, but can't explain why I can't rid the pool of it completely. And I'm very curious as to why the water does not get cloudy and why the powder is not yellow. When I go through the algae possibilities green clouds the water that's not what I have, yellow looks yellow, not white. And black algae is extremely rare in vinyl pools.
So I'm really wondering am I dealing with low levels of algae that bloom every once in a while that I have not completely gotten rid of? Or is it just deposits from the hypochlorate and putting in. Or something else. One clue for me is pool does cloud up when I shock it.

???

Heck yeah! Rangers fan living in CT...that's just awesome!

Yeah, strips are not reliable at all to be honest. They'll tell you that you have chlorine in the pool but the exact amount...not so much. As mentioned in my first reply as well as @Mdragger88 and @wireform, get either a TF-Pro or K-2006C test kit. It will be your best friend in regards to taking control of your pool. Also, make sure you read the Pool Care Basics link I posted above as well as the relationship between CYA and FC.

One more thing...when you get time update your signature so that we can see what all you have in terms of equipment, how you sanitize your pool (liquid chlorine (LC), saltwater generator (SWG), your pump type/manufacturer, etc. This will help everyone here offer you better advice. See the following link for tips. Create Your Signature - Further Reading

 

[rjd1965]

I've ordered the TF kit. I'm assuming my existing kit's reagents are expired.

In the meantime, I took a sample of the white powder and poured vinegar on it. It fizzed/bubbled, so I'm pretty confident I'm dealing with calcium not algae. And I am switching from using cal-hypo to liquid chlorine.

Hope this resolves it.

 

[cdadams1223]

I've ordered the TF kit. I'm assuming my existing kit's reagents are expired.

In the meantime, I took a sample of the white powder and poured vinegar on it. It fizzed/bubbled, so I'm pretty confident I'm dealing with calcium not algae. And I am switching from using cal-hypo to liquid chlorine.

Hope this resolves it.

Smart man you are! That TF kit will not let you down. Good thinking on the vinegar and glad it's not algae. Also, LC will not steer you wrong either. Pretty cheap at Walmart for the 10% Pool Essentials.

Make sure when your kit arrives that you read through the testing procedures (not hard at all) and then post your results as follows:

FC-
CC-
pH-
TA-
CH-
CYA-
Temp-


Calcium hardness (CH) doesn't really matter in a vinyl or fiberglass pool (I have the latter). As for salt...you'd appreciate the efficacy of a SWG over using only liquid chlorine (LC) all the time. Might want to consider one down the road as life is much easier. With a 35K gallon pool, make sure you research a SWG that is DOUBLE the size of your pool. Why type of pool equipment do you have, brand, etc.? Post pics of your setup when you get a chance.

 

[Rancho Cost-a-Lotta]

Calcium hardness (CH) doesn't really matter in a vinyl or fiberglass pool

I think I know what you mean, but just to be clear, low CH normally is not a problem in vinyl pools. However, high CH can still cause problems in a vinyl pool. Stay within TFP recommended levels. Moving to liquid chlorine/ bleach is a good idea. Switching to a SWG is good advice.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

 

[cdadams1223]

I think I know what you mean, but just to be clear, low CH normally is not a problem in vinyl pools. However, high CH can still cause problems in a vinyl pool. Stay within TFP recommended levels. Moving to liquid chlorine/ bleach is a good idea. Switching to a SWG is good advice.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

Thanks Mike! Yes that's exactly what I meant...low CH not an issue. I should have clarified that high CH could be an issue. Thanks for catching that goof!

 

[Mdragger88]

Hopefully it’s just the cal hypo but
To confirm or deny an algae problem do an Overnight Chlorine Loss Test.

 

[rjd1965]

A few days later... Water cleared from the cal-hypo shock I poured in. Bottom looking good, I'm feeling I solved the riddle with the vinegar test and then... This morning, white powder!
Ugh. No TF kit in the mail yet, so still using strips.
I just brushed it and will see what it looks like when I get home.

 

[Mdragger88]

We’ll be here!
Post em when you get em!