Instant Blue Green Suspension/Sludge during Winterizing

[PoolStored]

Do I need to be concerned about the 90% of "other ingredients" in the liquid version?

No. What liquid chlorine product are you using?

Do I need to be concerned about corrosive issues with a CH of 75? I am not turning the heater back on until I open the pool up in the spring.

No.

 

[celisup78]

I have this powder and this liquid. The liquid says 10% sodium hypochlorite, which I assume means 10% chlorine.

 

[PoolStored]

The liquid is excellent. Yes, 10% liquid chlorine.

The Cal-hypo is fine.

 

[celisup78]

After 6 hrs of running the pump, FC is 3.5, CC is 0.5, and TC is 5 or greater. Do I treat again based on FC number?

 

[PoolStored]

After 6 hrs of running the pump, FC is 3.5, CC is 0.5, and TC is 5 or greater. Do I treat again based on FC number?

You should only be testing FC with the FAS-DPD powder/reagent test. What was your FC from that test.
If you got your "TC" from the color comparator FC test, just stop using that test and use the FAS-DPD R-00870/R-00871 test.
If you are slamming, then add enough chlorine to go from 3.5FC (if this was from FAS-DPD) to your SLAM level FC. Use pool math to calculate.

 

[celisup78]

I used the FAS-DPD test for FC and CC, used the color comparator block for TC.

 

[PoolStored]

I used the FAS-DPD test for FC and CC, used the color comparator block for TC.

TC = FC + CC. We don't use TC.
The comparator block give you FC also, not TC. Just stop using the comparator block for FC.

 

[celisup78]

TC = FC + CC. We don't use TC.
The comparator block give you FC also, not TC. Just stop using the comparator block for FC.

Got it, I misunderstood what I read in the test book. I thought it said the chlorine comparator block was used for TC.

 

[PoolStored]

Sorry, I typed them backward. The comparator block gives TC, not FC.
In either case, just use the powder/reagent for FC and CC testing...

 

[celisup78]

My FC is not stable. After hitting it a second time at 4pm last night to increase from 3.5 ppm to 10 ppm....mixed for 6 hours, FC = 12 ppm at 10pm (I did add a little more than what pool math suggested)....shut down the pool for the night
.....turned recirc back on a 6am today , sampled at 10am....FC = 9 ppm......turned off recirc
....retested at 5pm....FC = 4 ppm

The pool was uncovered today, but it has been uncovered for the last 2 weeks. I dont think that can account for the pH dropping from 12 ppm to 4 ppm in 24 hours. Thoughts? Next steps? Thank you!

Currently vs (after water exchange)
TA: 70 (70)
pH: 8.0 (7.7)
FC: 4 (was 0, dosed, then 3.5, dosed, then 12, then 9, now 4)
CYA: 0 (0)
CH: 75 (75)

 

[PoolStored]

Without CYA in the water, I'm not surprised at the FC loss.

 

[celisup78]

I actually bought a 1 gallon of jug liquid stabilizer and conditioner today, 35% monosodium cyanurate monohydrate. Pool math calculates that will raise my CYA from 0 ppm to 30 ppm. I can add it. I read that I very slowly add it to the skimmer. Any concerns? Do I add it before or after adding liquid chlorine?

 

[PoolStored]

We don't generally recommend the liquid...it is more problematic and is more expensive.

For the liquid, Add it into the skimmer with the pump on full blast and let the water circulate for an hour or so. Do be a bit safer, you can try mixing it with a 5 gallon pail of pool water to make it thinner, then pour it in.

Don't neglect to rinse the bottle several times to get every bit of that liquid gold.

 

[celisup78]

I read scary stories about the dry powder causing issues due to lack of dissolving, especially since it is not summer water temps. But, yes, I noticed the dry was quite cheaper. I chose the liquid as I felt like I needed to, not wanted to given the conditions. I like the bucket dilution idea. How long after adding it before I can add more chlorine?

 

[wireform]

I concur with the above advice, if your closing soon then it's FC per the cya ratio, so 30 cya will give you a slam level of 12 and also get you PH into the low to mid 7's and call it done.

 

[PoolStored]

How long after adding it before I can add more chlorine?

Immediately.

 

[celisup78]

New day, new measurement. Last night, I added 1 gallon of liquid conditioner and 3/4 gallon of 10% chlorine (I was being a little conservative by 1 qt vs pool math's suggestion). Numbers are below. I am going to try and dial in the FC to 10-11.

Some questions:
1. Is it worth increasing the CYA to 35-40ppm?
2. Do I need to drop pH down closer to 7.5 using sodium bisulfate?
3. I read about the damage that low CH can do to a fiberglass pool and components. I have the calcium chloride hardness increaser on hand. Is it advised that I raise that CH level? If not, why not? Thanks!

Currently vs (before chemical addition)
TA: 70 (70)
pH: 8.5...guessing on the comparator block but it is above 8.0 (8.0)
FC: 8.5 (4)
CYA: 25 (0)
CH: 75 (75)

 

[PoolStored]

Some questions:
1. Is it worth increasing the CYA to 35-40ppm?

Not really, in the winter. Always round your CYA up to the next 10. If the dot is obscured at 25, your CYA is 30. Raise CYA in the spring.

2. Do I need to drop pH down closer to 7.5 using sodium bisulfate?

Use muriatic acid to lower pH. Sodium bisulfate adds sulfates which, when high, can damage concrete/plaster and metal parts. Only lower pH in .4 increments and test 30 minutes later. I wouldn't lower below 7.8 with a TA of 70.

3. I read about the damage that low CH can do to a fiberglass pool and components. I have the calcium chloride hardness increaser on hand.

CH is important for tile lines and your heater. Raising it to 200 is just fine.

 

[JamesW]

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[celisup78]

I think I am in a good place now. I added calcium chloride to bring up the CH.

Is a FC of 9.0 ok for winterizing a pool or does it need to be <3? Similarly, is a pH of 7.9 too high for winterization?

Current
TA: 80
pH: 7.9 (measured by digital pH meter)
FC: 9.0
CC: 0.5
CYA: 40
CH: 250