Startup and FC

Johnnie

Active member
Jun 3, 2019
29
Pinellas, FL
Pool builder's guy started us up yesterday, with a pouch of shock, two tri-chlor tabs in the skimmer and CYA and some chelant.

I brushed the plaster (pebble finish) yesterday afternoon and again this morning.

This morning, my numbers were:

FC 0.5
pH 7.2
TA 150
CH 375
CYA 50

Per Pool Math, I added approximately 50 oz of 10% bleach.

Rechecked my FC just now with the K1000 from my new TF-100 test kit and still showing 0.5 FC. pH rose to 7.5.

Air and water temp are both currently 76F

Dose more bleach?

TIA for any advice given.

 
I rechecked the FC using the FAS-DPD. When I added the powder, there was no discernible color change, though it did get cloudy. I added a several drops of the R0871 reagent, but the cloudiness didn't really clear, so I'm assuming I'm at basically 0 FC. I'm pretty good at discerning color, so I don't think I'm doing the test wrong. 5 drops from the bottle held vertical. My test should be accurate, I would think.
 
yeah, sounds like it. Are you adding the additional liquid chlorine? The "shock"product was half CYA, and those two pucks in the skimmer are probably still sitting there intact.

Maddie :flower:
.
Adding liquid chlorine (supposed) 10% from the closest pool store that does unfortunately have their bleach tank outside. They get fresh bleach every Thursday, but it may have lost some potency. The pucks are still sitting in the skimmer basket, barely consumed.

I added approximately 64 oz of bleach, which would raise FC by 7.2, which I know is toward the top of the range, but if the bleach has lost a lot of strength in the few days since I purchased it, help me finish my sentence.
 
What begs the question, if your supply is 10%, is it actually 10%, so 10% is 100,000 ppm, we can't really measure that, we can however if we dilute it, this is easy to do in metric,
because of the decimal shift nature of metric. You need 2 containers that hold 1L and a measure that can measure 10ml (typically your tester will accomplish this for you). Into the first container, put 10ml from your bleach bottle, and fill to the 1L mark with water, this will reduce the dilution by 100, so your 10% should be 1000ppm, still too high, take 10ml from this container, and put it in the second container, and fill to the 1L mark with water, this will again reduce the dilution by 100, take a sample from this, and measure your FC, it should be 10, it doesn't really matter if you get a lower number, this is your working strength. When your done, dump both containers into the pool, no sense in wasting it. One of the problems with pool stores and their bulk chlorine, you have no idea when it was actually manufactured, it could have sat in a big tank at the manufacturer for a year, then at the supplier for another year, and just arrived at the pool store last week, and that 10% is closer to 1%. You know there is no guarantee that the bottle of chlorine at Home Despot that is dated last week, was actually manufactured last week, just it was bottled last week.

Those who are mathematics experts will note you can use a 1ml sample in a 10L bucket, and get the same result with a single step which is true, however you need a pipette or a syringe to do it accurately and need a 10L container. 1L pop bottles are common, and you already have a 10ml measure in your test kit.

Mind you if I bought a 25L jug of chlorine at the pool store, that was advertised at 10% and tested it to find 1%, I would be ringing up the manager and making a complaint...
 
What begs the question, if your supply is 10%, is it actually 10%, so 10% is 100,000 ppm, we can't really measure that, we can however if we dilute it, this is easy to do in metric,
because of the decimal shift nature of metric. You need 2 containers that hold 1L and a measure that can measure 10ml (typically your tester will accomplish this for you). Into the first container, put 10ml from your bleach bottle, and fill to the 1L mark with water, this will reduce the dilution by 100, so your 10% should be 1000ppm, still too high, take 10ml from this container, and put it in the second container, and fill to the 1L mark with water, this will again reduce the dilution by 100, take a sample from this, and measure your FC, it should be 10, it doesn't really matter if you get a lower number, this is your working strength. When your done, dump both containers into the pool, no sense in wasting it. One of the problems with pool stores and their bulk chlorine, you have no idea when it was actually manufactured, it could have sat in a big tank at the manufacturer for a year, then at the supplier for another year, and just arrived at the pool store last week, and that 10% is closer to 1%. You know there is no guarantee that the bottle of chlorine at Home Despot that is dated last week, was actually manufactured last week, just it was bottled last week.

Those who are mathematics experts will note you can use a 1ml sample in a 10L bucket, and get the same result with a single step which is true, however you need a pipette or a syringe to do it accurately and need a 10L container. 1L pop bottles are common, and you already have a 10ml measure in your test kit.

Mind you if I bought a 25L jug of chlorine at the pool store, that was advertised at 10% and tested it to find 1%, I would be ringing up the manager and making a complaint...

Thanks for the tip on testing bleach, that's something I could actually do.

Do they make jugs of chlorine that big in Canada? Seems like that would be difficult to handle.

I purchased 2.5 US gallons (nearly 9.5 liter) for 4 USD. I don't want stale product, obviously, so I may have to shop around.
 
I would just say that Florida probably uses a LOT more liquid chlorine for pools through out the year than Canada. I would be less worried about chlorine strength being far lower than advertised and more likely fresh in Florida. In fact some folks have found theirs to be stronger than advertised its so fresh wherever they purchased it and when.

Maddie :flower:
 

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Current numbers:

FC 4
pH 7.5
TA 150
CH 300 (I measured it twice and came to the same result, I think my first measure was flawed. I'll keep an eye on it.)
CYA 50

I've got the magnetic stirrer now, so I'm more confident in my test results.

The pucks are dissolved and I dosed with 10% bleach today. I've added acid every day.

Got my routine down. Turn off spillways, set pump on high, test, dose, brush.
 
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PB tech is coming to start the SWG tomorrow.

Here are my numbers per my latest log:

FC 8.5 (had gone down to 3) adjusted with liquid bleach
pH 7.5
TA 90 (3 days ago)
CH 275 (I had measured it much higher earlier and am more confident in my testing now)
CYA 50
Temp 67 F
SALT (not tested)
CSI -0.27 (calculated)

I won't be home when they fire it up, but I will test the water when I get home.

The CH seems low to me. I measure it and get the same measure as my fill water, which I checked again this evening. I'm more confident in my testing with the speed stir. We had some evaporation and about 1/2" rain since the initial fill. I also added another inch of fill water from the hose.

Also looking forward to the end of the first month ban on vacuuming, though I may have cheated (one time) and used a brush vacuum head designed for a vinyl pool to pick up some chunks of stucco and pine straw that bothered me. I understand the reason not to use the roller head on curing plaster and it's still in the plastic packaging. Hope they'll send somebody out to show me how to use the Dolphin Echo.

Thoughts from the hive mind on what comes next? Should I increase the CH if it's still at the current level after the SWG comes online?
 
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