Questions on chlorine/liquid chlorine

[superdave5599]

Our SWG cell finally quit over the weekend, so I stocked up on LC. (All 12.5% labeled.)

On Sunday morning, I tested 5.5 of FC and added a gallon (that gallon I had bought in late April. All the rest were produced mid-July). Sunday afternoon and evening I tested 9. By Monday evening, it dropped to 5.5, so I added 2 gallons and we put the solar cover on. (I am being a little paranoid about accidentally letting it drop, as I had gotten used to only needing to check every few days and we'll be out of town for the upcoming weekend.) After about an hour and a half, it tested at 11.5 but Monday morning it tested at 13.5. So I presume that it just hadn't fully mixed even though time-wise it should have. Cover stayed on all day Monday and until yesterday evening. I was surprised that I tested it at 13 ppm still! I would have guessed with the "clear" (not blue) solar cover I'd have lost more. There were some puffy clouds here and there, but I would have described most of yesterday as sunny.

Does all that seem about right?

I have a tracking number, but by that number the new cell hasn't actually been picked up by USPS yet, so at this point I would be surprised if I can get it installed before we leave Friday at noon. So my plan is to just make sure the FC level is still high before I go to work Friday morning. It is going to be HOT again over the weekend so I probably would have left the cover off, but I suppose it'll be OK to leave it on to help preserve the chlorine.

Thoughts? Am I on the right track?

 

[Mdragger88]

If your cell hasn’t arrived by the time you need to go raise fc to slam level for your cya FC/CYA Levels & deploy the cover.
Your last cya result (80ppm) was a month ago is that still your cya?
Also what replacement cell did you get? Another 40 or a 55? You have a big pool.

 

[superdave5599]

I can certainly check the CYA level again, but I don't think it has changed much really. Seems like we don't get tons of splash out, and since I learned about the hairnet over the skimmer basket trick, I haven't needed to backwash the filter much either.

I was mostly surprised at how little chlorine seemed to be used-that the solar cover provided that much protection! (Or, maybe it was cloudier than I realized yesterday?) I'll be anxious to check the level again later this evening.

I think I bought 8 jugs of bleach on Sunday, anticipating that I'd need about a gallon per day on average. Pool Math says a gallon will raise my FC a touch over 4 PPM. And since I started at 5.5 then added 2 gallons and had 13.5 early Monday morning, that seems to be about right.

 

[Mdragger88]

If you’re just going to be gone a couple days you can add whatever your normal daily loss is x’s however many days plus a few extra ppm for insurance. The solar cover really helps alot with protecting fc from the sun.
Did u get a 40 or a 55 replacement cell?
The universal 55 is the ideal size for your pool volume.
I am pretty sure they are interchangeable (the cell size may need to be changed in the settings) but that may depend on the age of your setup as they didn’t used to make a U55.

 

[superdave5599]

Sorry, I forgot add that bit of info!

Yes, I did go ahead and upgrade to the 55 when I called them. I was happily surprised to find that they had record of the original purchase from the previous owners of the home, and there was still some warranty time which they transferred to me, so that knocked off about $150!

Slightly annoyed because I was told it would go in the mail either that day (Monday) or yesterday but the tracking didn't show it as having been picked up by USPS until late this afternoon.

I haven't had to add anything on a normal daily basis yet, really, as the SWG didn't go out until this past weekend! So the baseline I've got is very minimal. But I am tracking it close to try to get a bit of one.

 

[superdave5599]

I tested again tonight.

CYA looks to be between 70 and 80, so of course we call it 80.

But, seemingly strangely, chlorine is still testing at 13. I did it twice tonight, one with the powder kinda heaping in the scoop, and one not heaping.

Even though I'm using the cover (besides a little swimming last night and this evening) it seems really strange that the chlorine hasn't really dropped in a couple days.

I suppose I shouldn't really be worried, everything is nice and clear and all that. But it seems strange enough that this makes me worried!

Should I be?

 

[Newdude]

I suppose I shouldn't really be worried, everything is nice and clear and all that. But it seems strange enough that this makes me worried!

Never be worried when you're free and clear above minimum. Maybe it takes 2 days, maybe it takes 2 weeks but the sun will deplete your chlorine and there are no two ways about it.

As long as you have enough FC to remain above min by tomorrow's test, you're golden.

 

[superdave5599]

Never be worried when you're free and clear above minimum. Maybe it takes 2 days, maybe it takes 2 weeks but the sun will deplete your chlorine and there are no two ways about it.

As long as you have enough FC to remain above min by tomorrow's test, you're golden.

Ha ha, ok, ok.

I'll do my best to not worry about it!

 

[superdave5599]

Welp, to probably wrap this thread up:
Last Thursday evening I tested at 11.5 ppm so I added 4 gallons of bleach and brought the pool to 24.5 (tested Friday morning). When we returned Sunday afternoon I still had 16.5. Installed the new SWG that afternoon. Have it set for a very low percentage (like 5%); it tested at 14.5 yesterday evening.

One question about the new cell, though:
The salt readout that is the default PPM is back to reading 3200ppm, which is what it was pretty consistently reading up until the cell stopped working. (Upon reflection, it was inching lower close to when it quit, but that is the number I would usually see.) Instant reading was just at 3500. My level is much closer to 4,000 (tested twice). Should this cause concern? I'd been reading that it is often a sign of a dying cell when it is reading too low. Thanks!