New with a couple of issues

[rsmoore27]

Hello all. I currently have a pool company that maintains our pool at a new house. They haven’t been impressive since we moved in in June, so I’ve been planning on taking over for awhile now. After swimming this weekend, felt like the pool was starting to look like there might be a tint of green which was concerning. I then noticed that the cell light was flashing on the SWG, so I don’t think it’s generating any chlorine. Not sure how long it’s been like that. Went ahead and worked through all of the testing using the TF-100 kit and didn’t find anything good. It was my first time using the tests, but I’m pretty sure I did them right. Here’s what I found:
FC - no measurable
CYA - no measurable
Ph - 7.8
TA - 60
CH - 250ppm
Salt - 3000ppm

So.... several things to do. I obviously need to get the cell checked out, but I thought think it’s likely going to need to be changed. Per the stamp on bottom, it was manufactured in 2012, so I think it’s likely old, not just dirty.

In searching about the checking the cell on the forums, I saw a comment that suggested a priority would be to add chlorine as the SWG wasn’t working. That made sense to me and it was then that I tested and found out that I have no chlorine in the pool. In addition to an overall plan, my first priority is what should I add to the pool now to keep chlorine in there. Do I add CYA or chlorine first. The goal is to get the pool clean and stable while I can determine for sure if I need to change the SWG and, if so, get it done.

Thanks in advance for any help. This forum has already taught me a ton.

 

[YippeeSkippy]

RSAMoore, hi there- we'll help you figure this all out.

Did you run the CC portion of the test immediately after running the FC test? What were the results?

Next- I want to confirm that your CYA result was that you ended up filling the tube entirely to the top and could still see the dot, right??

Maddie

 

[Dirk]

Work with Maddie regarding the chemicals. In the meantime, you might try this. I believe this doesn't work with all models, but I'm not sure when the date cutoff is that they added it:

IntelliChlor SCG Usage Hours Meter
The IntelliChlor® SCG provides a built-in cell “usage hours” meter that reports how many hours IntelliChlor has been operating. The IntelliChlor SCG is designed to operate for approximately 10,000 hours before replacement is needed or roughly five (5) years of average use.
To access the system status mode:

1. Press and hold the MORE button for three (3) seconds until the lights scroll across the unit.
2. One (1) of the five (5) Sanitizer Output LED indicators (20%, 40%, 60%, 80% and 100%) will be lit,
   indicating the hours of usage. The Output LEDs are as follows:
   • 2000 hours (20% LED on)
   • 4000 hours (40% LED on)
   • 6000 hours (60% LED on)
   • 8000 hours (80% LED on)
   • 10,000 hours (100% LED on)

If the LED lights scroll and then the 100% LED lights up, it's done.

 

[Wobblerlorri]

You should retest your chlorine using the FAS-DPD test, then immediately afterwards do the Combined Chlorine test. That will let you know if you have any organics working in the water and whether you need to start a SLAM. If your CC is over 0.5, it's SLAM time.

SLAM Process

You need to add chlorine ASAP. Go ahead and add enough liquid chlorine to give it an FC (Free Chlorine) appropriate to a CYA of 70. Then add the appropriate amount of CYA to bring you up to 70 using the sock method: Weigh out the dry CYA into a white cotton sock, panty hose, or filter sock, tie it off, then hang it in front of an outlet. Let it soak for about an hour, then go out and squeeze the sock until it's all dispersed. Takes about 15 minutes to get it all squeezed out.

You need the higher CYA because you have an SWG.

I think you may need more salt, but I'm not an expert on salt water pools. SWGs are too rich for my blood!

 

[rsmoore27]

Thanks all for the thoughts. Those are helpful.

Maddie and Wobbler, I did not run the CC portion of the FAS-DPD test right afterwards. To be honest, when the water didn't turn pink after adding the R-0870, I was kind of stunned and didn't think about going further. To rerun the test, specifically to test for CCs, I'm assuming I start the same way and add the R-0870 again, then since the water won't be pink, skip the R-0871 altogether and go straight to the part where I add the R-0003 for the CC test? As far as the CYA test, yes, I filled the tube completely, a couple of times and never was able to obscure the black dot. I'll test again this afternoon, but I think I was doing it right. Tried inside and outside, with several different samples from the pool. Anyone have any thoughts as to what's more likely - me screwing the test up, or there really not being any CYA?

Dirk, thanks for the tip on testing the SWG. I'll knock that out as soon as I get home this evening and see if it gives me any feedback.

Tentatively, my plan for the evening is:
- Retest, including CC levels
- Assuming all is the same (i.e. I haven't completely screwed up the tests), I'll then add:
- 96oz of liquid chlorine (10% solution)
- 140 oz of CYA (per Pool Math to raise from 0 to 70).

Does that seem like an appropriate level of CYA to add? I see the recommendations for suspending in a sock and the image that pops into my head doesn't have 8lbs of material fitting in a sock, so I wanted to confirm before moving forward.

 

[rsmoore27]

Also, I did have one other question I wanted to "ask the experts." At my previous home, I had a pool guy that I really liked. He's a nice guy, ethical and logical, and I didn't have a single issue with the pool in over 4 years. When I asked if he'd service my new pool, we were too far. When I told him my new pool was saltwater, his suggestion was to wait until the cell failed, then convert back to a freshwater pool. His main argument seemed to be centered around the fact the SWG is going to fail every few years and it'd cost $700 or so to replace, so by moving back to freshwater, I wouldn't have to worry about that concern.

Anyone have any thoughts, not only on which is preferable (I'm pretty agnostic at this point), but what the process of converting would look like? Could I simply put a dummy bypass cell where the SWG is and then start managing the chlorine process manually? Or, would I need to drain the pool, refill and start over with freshwater? My gut is to simply replace it at this point, but curious what the consensus opinion is these days.

 

[mknauss]

Do not add CYA to 70 ppm right now. Add to 30 ppm. As you are entering winter, the SWCG will not need the CYA protection level so high.

Most members here with a SWCG would fill in their pool before getting rid of their SWCG. The reduction is maintenance time and the process of buying, transporting, and storing many containers of liquid chlorine is just not attractive at all. The economics of the SWCG are about a wash. Your SWCG will generate chlorine for about 10000 generating hours. That amount of chlorine will be a wash (approximately) with the cost of purchasing liquid chlorine over that period.

If you wish to return to a manually adding liquid chlorine EVERY DAY to your pool, there is no need to drain the pool. All pools end up with salt in them. Most in the 1000 ppm range though we have seen some with in excess of 5000 ppm salt from using chlorine products (liquid and solid) plus muriatic acid.

 

[rsmoore27]

Thanks for the thoughts mknauss. My gut was to replace the SWCG and move on. From a maintenance standpoint, it definitely seems like the way to go. Also, thanks for the thoughts on CYA to 30 instead of 70. Targeting 30 instead of 70, I'm assuming I should also reduce the amount of liquid chlorine I add based on the Cl/CYA chart?

 

[mknauss]

Correct. Follow the chart for that level of CYA. A SWCG will shut down at water temperatures in the range of 55F, so you have to add liquid chlorine during the winter. Not as often, but you do need to test every week or so once the water temperatures drop below 60F.

 

[YippeeSkippy]

My first cell lasted near 9 years, and cost about $399. to replace. I suspect your old pool guy is kinda clueless to Salt Water Chlorine Generators (SWG).

Maddie

 

[Stoopalini]

His main argument seemed to be centered around the fact the SWG is going to fail every few years and it'd cost $700 or so to replace, so by moving back to freshwater, I wouldn't have to worry about that concern.

Food for thought, assuming you spend $600 on a new SWCG every 5 years, for a 14k gallon pool:


How much FC can you replenish per day, for 5 years, given $600 of 10% liquid chlorine:

At $4 for a gallon for 10% chlorine, $600 buys you 150 gallons.
Converted to ounces (128:1), that's 19,200 ounces.
Spread across 5 years (1825 days), that's only 10.5 ounces a day.
10.5 ounces of 10% equates to about a 0.56ppm rise in FC for a 14,000 gal pool.


How much would you spend to replenish 2 FC per day, using 10% liquid chlorine, for 5 years:

2 FC equates to 36oz in a 14,000 gal pool
36oz per day, for 5 years (1825 days) is 65,700 ounces
Converted to gallons (128:1), that's 513 gallons
at $4 per gallon, it's a total of $2,052 over the 5 year period.


How long would $600 worth of 10% last with a 2 FC per day requirement:

$600 buys 19,200 ounces at $4 per gallon
19,200 ounces divided by 36oz (amount needed to replenish 2 FC for a 14,000 gal pool) is 533 days
533 days is 1.46 years


Obviously, how big your pool is, and how much FC loss you have due to the sun, swimmer load, organics, etc ... all play a part here. As well as how much liquid chlorine costs if your area ... I just used 14,000 gallons, $4, and 2 FC as the example. But ... anyway you do the math, replacing the SWCG every 5 years is still cheaper than using liquid chlorine for the same time period. And ... if yoiu follow the TFP method, chances are your generator will last more than 5 years (seems like your current one lasted 8 years).

 

[Dirk]

Most excellent write up, Stoop! And of course, you left out the math to equate the driving and lugging and storing and pouring of liquid chlorine (every day!). I've said before, I wouldn't care if an SWG cost twice as much as using liquid chlorine.

 

[YippeeSkippy]

Of course, there is also a value in convenience. How much my time and effort are worth in fact make a SWG even cheaper.

Maddie

 

[HermanTX]

Food for thought, assuming you spend $600 on a new SWCG every 5 years, for a 14k gallon pool:


How much FC can you replenish per day, for 5 years, given $600 of 10% liquid chlorine:

At $4 for a gallon for 10% chlorine, $600 buys you 150 gallons.
Converted to ounces (128:1), that's 19,200 ounces.
Spread across 5 years (1825 days), that's only 10.5 ounces a day.
10.5 ounces of 10% equates to about a 0.56ppm rise in FC for a 14,000 gal pool.


How much would you spend to replenish 2 FC per day, using 10% liquid chlorine, for 5 years:

2 FC equates to 36oz in a 14,000 gal pool
36oz per day, for 5 years (1825 days) is 65,700 ounces
Converted to gallons (128:1), that's 513 gallons
at $4 per gallon, it's a total of $2,052 over the 5 year period.


How long would $600 worth of 10% last with a 2 FC per day requirement:

$600 buys 19,200 ounces at $4 per gallon
19,200 ounces divided by 36oz (amount needed to replenish 2 FC for a 14,000 gal pool) is 533 days
533 days is 1.46 years


Obviously, how big your pool is, and how much FC loss you have due to the sun, swimmer load, organics, etc ... all play a part here. As well as how much liquid chlorine costs if your area ... I just used 14,000 gallons, $4, and 2 FC as the example. But ... anyway you do the math, replacing the SWCG every 5 years is still cheaper than using liquid chlorine for the same time period. And ... if yoiu follow the TFP method, chances are your generator will last more than 5 years (seems like your current one lasted 8 years).

I like the breakeven analysis - sort of what I did to evaluate when I should start taking social security payments and had to make assumption on my expiration date (i.e. FC loss per day)!!!!! For someone that has an existing SWG and just to purchase a cell it makes sense. You would need to include the total cost of a SWG system and installation if starting from scratch. Just need to adjust the breakeven costs. Thanks for putting this out there for all to consider.