sporadic white foam floating on surface of pool

[Jenmachen]

we had two snow days in a row, very rare for our area. feels like the whole neighborhood was in my pool.

for the first time in my pool's history, my chlorine dropped down to less than 1, with free chlorine at 0.5. Other results were within range: Ph at 7.6, ta at 80.

for the first time, i used the "Boost" mode on my pentair intellichlor SWG. I let it run all night, about 10 hours. I retested this morning:

TC at 5
FC at 5
ph at 7.8
ta at 70

i added a pint of muratic acid. but that is something i do twice a week anyway.

there is a spattering of white foam floating on the surface of water. it's not thick or fully covering. any idea what's going on? water is crystal clear.

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ok, now even stranger......the foam is gone. all i've done in the past 30 minutes is: knock my SWG back to 3 blinking lights (I think that is 6%), and add a pint of muratic acid, which i do twice a week anyway

 

[mknauss]

First - always better to use some bleach to bring FC up quickly versus using your SWCG.

Only reason for foam would be very low CH, the addition of some types of algaecide, or scented/splashless bleach.

How are you testing FC? FAS-DPD?

Take care.

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What make/model of SWCG? Can you add more detail to your signature? See Pool School - Getting Started

 

[Jenmachen]

Ok, I have never needed to use bleach. I (wrongly i guess) assumed the SWG could bring it back up. Why would I rather use bleach?

As for testing, I bought the taylor kit recommended by TFP last year. But I did not understand any of it. I realize that makes me sound like an idiot. I read instructions, re-read, re-read. Chemisty is easily my worst subject.

I went back to my aqua-check 7 strips. I do test every single day. And I take samples to two separate pool places for testing every other Friday. They have stopped trying to sell me anything, they know i'm just going to test. I use two stores specifically because I have no way of knowing how often they calibrate those machines, and two readings will at least help confirm my own readings, or alert me to anything I'm not seeing in my own tests.

My CH is 200 on my own test strip, and last friday the pool stores tested it at 196.

I have also never used algaecide or anything like that in my pool. I have had nothing but crystal clear water for a year. The chlorine levels were too high upon installation of new equipment a year ago, but after letting them fall naturally, I have never had a moment of trouble.

I use muratic acid twice a week. I have used baking soda a few times this year when called for. I raised my CH with de-icer a few times this year.

We do swim nearly every day, and on the weekend can have a heavy swimmer load. It is my habit, to slightly raise my SWG setting on Friday, and put them back down on Sunday evening.

 

[mknauss]

I really recommend using your test kit.
There are YouTube demonstrations on doing the tests with the TF100 kit -- see TF-100 Test Kit - YouTube
The Taylor kit is pretty similar except I believe the CYA test is different. Have never used a Taylor kit.

Using 'Super' on the SWCG just wears it out really quick. And it is pretty slow in putting the chlorine in the pool. With bleach, you put in 3 quarts of 8.25% bleach in your pool and you have FC 5 immediately.

I hope you test your pH prior to adding acid. You should not need to add baking soda if you are adding acid. Means you are pushing your pH too low. Try keeping pH at 7.8 and see if it stabilizes.

Foam could have been from someone having left over shampoo in their hair or soap in their swim clothes. Then running the pump longer than normal sheared it into foam.

Take care.

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Also -- three lights on an IC40 is set at 60%. I would not think your indoor pool would need that setting unless you have a nascent algae issue.

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Another item! Please add your pool pump to your signature. I assume you do not have automation.

 

[Jenmachen]

Not three SOLID lights on my SWG, that would be 60%. During the week, I keep it at three BLINKING lights. I checked and that is 6%. My indoor pool has no direct sunlight, and the low SWG setting keeps my chlorine perfect. I do test the PH every day. It creeps up through the week, about a tenth of a point a day. I do not know why the PH creeps up. And twice in the past year, the TA was low, so I add the soda.

I was wrong about the taylor kit. The kit I bought was the TF100 kit. I definitely understand that you recommend using that kit. And I promise....I am a fairly smart girl. And I am normally just a rule follower. So, when I ask for your advice, I normally just obey as though I were speaking to my own dad. But that test was the most confusing thing I've ever encountered.

I have never had algea of any kind.

I didn't realize the boost mode would wear my SWG out quicker. I will not use that again. I will pick up the bleach and follow your advice. Although in 12 months of operation since our new start-up after buying the house, that is the first time my chlorine levels were too low. But I do watch the numbers very carefully every day, and adjust the SWG accordingly. There are times when I drop it down to 4% for a day or so.

 

[mknauss]

Great -- you have a newer version of IC40 that can be set at lower %'s without automation.

I really suggest viewing the YouTube videos on the testing.

Bleach does degrade over time. So do not stock up. But it is useful to have if you have a high bather load and can just put in a quart or so instead of messing with the SWCG setting.

Take care.