New(er) pool owner, very stubborn brownish stains

[emf411]

My pump has been continuously running for the SLAM and I've had my vacuum in and running since last night.

5:00pm
FC 17.5
CC 0

I lost just a little FC during the day today.

I can try taking the ladder out possibly tonight and leaving it out overnight.

If I still can't hold FC for the OCLT, what's next? I keep my cartridges clean (I have 2 that I rotate) and they are both about 5 years old, could this be a potential trouble area?

 

[Mike1162]

Here is my latest OCLT test:

8:45pm
FC 28.5
CC 0

6:20am
FC 21
CC 0.5

My FC still seems to be dropping overnight more than 0.5 for some reason..

Did you add any chlorine after this mornings test showed 21?

 

[emf411]

Did you add any chlorine after this mornings test showed 21?

No, I haven't added any chlorine today

 

[Mike1162]

It's strange that you lost 7.5 ppm overnight & 3.5 in just about the same # of hours during the day. We sure didn't have much sun today, maybe the chlorine is finally starting to hold. Try another OCLT tonight.

 

[emf411]

Yeah I thought the same thing, but maybe it is finally stabilizing.

I just tested at 8:10pm

FC 19.5
CC 0

My FC actually went up on it's own since my last test at 5pm, hopefully that's good! I just added some chlorine to raise the FC for the OCLT.

 

[emf411]

Looking better this morning.. after I tested at 8:10 last night I added a little chlorine.

9:05pm
FC 20.5
CC 0

6:15am
FC 17.5
CC <0.5

 

[emf411]

Alright, I'm starting to feel better. I just tested:

5:10pm
FC 15
CC 0

The chlorine appears to be holding pretty well, I haven't put anything in today. My wife and kids used the pool today, and it's been pretty sunny all day.

Should I do another OCLT tonight?

 

[lightmaster]

I'd say yes, make sure it's just the sunlight using up your chlorine now.

 

[Mike1162]

Yeah, your numbers are looking good but check it tonight & make sure.

 

[emf411]

Still looking OK I think.

8:30pm last night:
FC 13
CC 0

7:45am this morning:
FC 11.5
CC <0.5

 

[Mike1162]

I'd continue the slam through the weekend to see if you can get the overnight loss less than 1 ppm. I also had trouble getting below the 1 ppm threshold. Mine might have been due to the large number of insects committing suicide every night.

 

[lightmaster]

If you’ve got a leaves or insects falling into you pool, try covering it up at night. Just make sure you don’t have any grass clippings or anything on the cover first.

 

[emf411]

Still holding pretty well, I brought my FC back up yesterday but wasn't able to test regularly..

1:50pm (Saturday)
FC 28
CC < 0.5

9:10am this morning, without adding anything since yesterday around noon:
FC 24
CC 0

 

[Mike1162]

Sounds like you might be there. Try the OCLT again tonight if you can. If possible add chlorine around 8:30 & give it a whole hour to circulate before testing.

 

[emf411]

So an interesting update this morning. Last night I brought my FC up pretty high, I added a full jug at 7:30pm then tested a little over an hour later:

8:45pm
FC 30
CC 0

This morning at 6:20am
FC 18.5
CC 0

We had a lot of rain early this morning which could be related, but the only other thing that changed was that I shut off my heater at 7:30 last night when adding the chlorine. Does water temperature or having the heater on or off during a SLAM matter? I didn't think it did but now I'm wondering..

 

[Mike1162]

Heater won't make a difference & we sure didn't get that much rain. All I can think is the chlorine wasn't thoroughly mixed in.

 

[emf411]

Sounds good, I'll keep trying the OCLT's.

At 7:00pm:
FC 20
CC 0

I haven't added any chlorine today. I'm not going to add anything tonight, I'll see how it is in the morning..

 

[emf411]

I tried a somewhat aggressive approach today and sprinkled 3 x 12 oz bags of granulated Cal Hypo 73% on the stains and it made a noticeable difference in lightening up my brown stains. I'm wondering if it is some type of algae. The Cal Hypo brought my FC up to 37.5, and a test 2 hours later the FC was at 36. I'm going to try to maintain it above 30 for the next few days to try burn off whatever it is.

Shortly after adding the granulated shock, the shock caused some of the water above the stains to turn green and the water also became a bit cloudy.

My CC has been testing between 0 and less than 0.5 so that I think is a good thing.

 

[lightmaster]

You might try rubbing a chlorine puck on the stains. Probably easier than using Cal Hypo

 

[emf411]

I initially did try that when determining that I have organic staining. The puck did lighten the stain, but after a period of time the stains became darker - maybe that was because at that point my FC was at 0?