Salt Cell doesn't seem to be doing the job

[Scout101]

Pool's been fighting me a bit this year. Thought I had it all set up, passed the SLAM last weekend, etc. Noticing that my salt cell (T-Cell-15) doesn't seem to be keeping pace, and I'm losing FC. 26k gal pool, used to running it in 2 blocks of 4 hours each, 55% for the SWG, and not having problems. Looking for help with what I should be expecting.

-What's the expected FC drop that I'm trying to make up for? CYA should be 80 (reads 70 but just put in enough to finish that off to 80 the other day).

-Ignoring past numbers, what should I be doing for pump run time and percentage? I just bumped it up to 100% before I left for work this am, see how it looks when I get home. Also moved timer to 10 hours vice 8. Briefly played with 70% and 9 hours, but it was 2.5 FC this morning, so wanted to see if I could get it to increase.

-FC was 5 Monday mid-morning, 2.5 this morning around 7am. Pool had previously tested with 0 CC, but popped pink this morning, will reverify tonight.

Was hoping to avoid another SLAM since bleach is $5/gallon and my CYA is now 80, but if I have to go again, I will.

Salt Cell is new as of last year. I'm in Rhode Island, so it's not a heavy use pool area. Was used June-End of September, and then just activated at the end of my SLAM last week. Salt is reading 3300, volts/amps read around what I'm used to seeing on the diagnostic screen, and I see gas bubbles from the nearest return jet when it's running so it seems like it's making gas but can't really verify and no idea if it's not doing as much as expected, etc. With the end of my SLAM, was hoping I was ready to turn it over to automation and enjoy the pool, but not yet. Plus side is that it still looks nice and clear, so no visible issues. I did note that I had very low readings for CH (vinyl pool so never cared much about it), so added enough calcium chloride to get back to 250.

Appreciate any help, hate to run around tossing $5 bills in the pool all day so want to figure out the root of this issue and get things back to trouble-free. Thanks!

 

[mknauss]

The SWCG is set to add 1.2 ppm FC per day to your pool. That is likely way too low for this time of year.
Run it 24 hours per day at your 55% or raise it to 100% for 12 hours and see if your FC is better managed.

Those setting will create 3 ppm FC per day or slightly more.

 

[Scout101]

Thanks, will start there (100% for 12 hours) and see what it looks like. Not sure why it used to work at the lower settings, but maybe I was just lucky. Also had more shade in previous years, a bunch of trees are now firewood so I get more sunlight and it's a south-facing pool. Also a new SWG as of last year, so we don't have a nice trusting relationship yet

 

[pjt]

26k gal pool, used to running it in 2 blocks of 4 hours each, 55% for the SWG

That increases your FC by only 1.2 every day, which is nowhere close to enough. Use PoolMath --> Effect of Adding --> SWG. (Your 24 hour SWG output is 1.47.)

What's the expected FC drop that I'm trying to make up for?

Start with ~3 every day. It's better to have too much FC than not enough.

 

[Scout101]

Saw in another thread while posting this one that sometimes a big Calcium Chloride addition will (for maybe unknown reasons) cause a big FC drop? Interesting comment if true, as I fed the pool a 50lb bag of ice melt (95% calcium chloride, was on the ok lists from other posts about this) to get the CH up to 250. Was barely registering before, so maybe that big boost in a short window caused me trouble? Added it all on Saturday night, just a day or so after SLAM conclusion.

And yes, onboard with cranking the SWG. Once I get it to a point where it overshoots, easy to turn down. Just want to see the number go up at all first

 

[mknauss]

Your choice of course, but with a vinyl liner, that level of CH is not needed.

 

[Scout101]

Your choice of course, but with a vinyl liner, that level of CH is not needed.

Not a number I bother to chase, and usually don't even test it. Just realized I hadn't tested it in probably a year or more, so did it and it turned blue on the first drop. Nothing to overly hurt in a vinyl pool, aside from the mechanics and the ladder, I guess, but figured $20 for a bag of ice melt was worth 'fixing' it. I try to keep it all in the nice happy range to make PoolMath app pleased with me.

Had a tear in the liner in the spring, and lost a good chunk of water I had to replace from the town water, so decided it was a good time to dial back in.

 

[mknauss]

I try to keep it all in the nice happy range to make PoolMath app pleased with me.

Range for CH for a vinyl pool is 0-650 ppm.

 

[Orion7319]

Also had more shade in previous years, a bunch of trees are now firewood so I get more sunlight and it's a south-facing pool.

Bingo, plus it’s probably hotter this summer. I know it is where I am.

 

[Scout101]

Pleased to report I tested 4 fc and 0 cc this morning, so looks like the swg may be ok after all and I was under running it. That was at 100%, probably about 10 hours. Currently set for 100, 12 hours today, so as long as it keeps going up, I can start to dial it back down until I’m sitting steady around 6-7ppm.

Appreciate the help, you guys are great like always. Really didn’t have a SLAM in me this week, and didn’t look forward to chasing a faulty swg that was a couple weeks out of warranty, so thrilled that it was the easy answer for a change