Strange Salt Cell Issue

[diesel1218]

Morning, is it normal to drop so much FC over a week? I tested a little over a week ago and now I am showing FC of 7, now we did have a lot of rain this past weekend.

 

[Mdragger88]

Morning, is it normal to drop so much FC over a week? I tested a little over a week ago and now I am showing FC of 7, now we did have a lot of rain this past weekend.

Your fc was 14.5 nearly 2 weeks ago. The pool comsumes fc every day. A consumption of .5ppm /day is not unusual & in fact it may be a little low depending on your weather there.
The average residential pool consumes anywhere between 1-5ppm fc/day give or take depending upon conditions & the season. Less in the cooler months and on the higher end of the spectrum in the dog days of summer.
You do not want fc to fall below minimum for your cya or algae will grow so set your swcg or dose with liquid chlorine accordingly FC/CYA Levels
You should be testing fc every few days.

 

[Newdude]

The average residential pool consumes anywhere between 1-5ppm fc/day give or take depending upon conditions & the season.

+1. And just because we never clarify this enough.....

1 ppm a day (or so) now.
5 ppm a day (or so) in July.

There is a sloooow but steady increase from now until the mid season, then a steady decrease of daily FC loss for the back half of the season. (Think of a bell curve). There may be a whoopsie week here and there that goes a little sideways, but for the most part it follows the schedule.

 

[JamesW]

we did have a lot of rain this past weekend.

Make sure that the water is well mixed after a heavy rain before testing.

 

[diesel1218]

Make sure that the water is well mixed after a heavy rain before testing.

Yeah it did not rain yesterday and I waited a good two hours after the pool came on today. Just wanted to make sure it wasn't abnormal to go from 15 to 7 in roughly a week. The sunlight isn't out right now so I can not see the CYA but my other test were FC 7, CC .5, PH > 8, CH 325, TA 100

 

[ajw22]

Just wanted to make sure it wasn't abnormal to go from 15 to 7 in roughly a week.

Do a Overnight Chlorine Loss Test to confirm nothing abnormal.

If you pass the OCLT then you know your pool uses about 1ppm of FC per day this time of year.

 

[diesel1218]

Do a Overnight Chlorine Loss Test to confirm nothing abnormal.

If you pass the OCLT then you know your pool uses about 1ppm of FC per day this time of year.

Okay so basically since I dont plan on adding anything today. My SWG is still off until the FC comes down in range. Just test in the morning before the sun hit the pool again and I should be no less than 6?

 

[ajw22]

Okay so basically since I dont plan on adding anything today. My SWG is still off until the FC comes down in range. Just test in the morning before the sun hit the pool again and I should be no less than 6?

Test after sunset and then before sunrise and you should get the same result within one drop.

 

[diesel1218]

Test after sunset and then before sunrise and you should get the same result within one drop.

Good Morning so when I tested again last night it was 7.5 FC and this morning same result 7.5 FC.

 

[ajw22]

Good Morning so when I tested again last night it was 7.5 FC and this morning same result 7.5 FC.

Then you are good with normal FC loss of 1ppm per day.

 

[diesel1218]

Just an update here, new SWG was installed today, they rolled back the version to the 940 model. SO far so good it is reading 3260ppm average salt and 3191 ppm instant salt. Only been running for a few hours now.

I guess with this the FC levels will be good to monitor now. This morning it was down to 5.5 FC and my Ph was still over 8 so I added 22oz acid to help bring that down. (my pool size is a bit of a mystery to me, when I calc it based off dimensions I get just over 15,000, my water letter to the county stated 18,000 gallons, but checking the water bill from when it was filled was closer to 15-16,000.)

It will be interesting to see how the SWG does with the FC levels. It is currently set at 50% so I assume I want to be able to maintain the 5.5FC level since it is in the middle of the suggested range. I guess I play with the 50% until that happens?

Let's hope this SWG last as my last one worked for 3 weeks.

 

[kul]

Just finished reading this thread. I always love the transitions when someone learns how to manage their own pool! We all started in similar positions. Sounds like you got a great handle on testing and that you’re likely realizing you don’t necessarily need your pool tech.

 

[Newdude]

the 940 model

Ok so at 16k gallons it should produce about 1/2 FC per hour 'on'. At 15k gallons it's .45 per hour.

50% of 6 hours is 3 hours on. 100% of 3 hours is 3 hours on. (Etc etc).

I assume I want to be able to maintain the 5.5FC level since it is in the middle of the suggested range

That range is fine in the earrrrrrrrrly FL season right now as you aren't losing much FC per day. When the daily loss ramps up with the longer days and higher sun angle, you'll want to maintain the upper side of the range to allow some wiggle room. You could very well lose 5ppm a day in sunny FL mid season. If you're running a 5.5 you'd be below min with one afternoon's worth of SWG hiccup.

I caught mine shutting off for 12 hours due to reading low salt during/after big rains 7 or 8 times last sesson. 1 inch of rain is less than 1/60th of my pool, but if the pool isn't well mixed yet the cell might be testing mostly fresh water on top. This is particularly an issue for those that don't run 24/7. The pool kicks on hours after the storm and the SWG runs its self check with mostly fresh water. Then it shuts off until the next self check.

Although you technically don't need much wiggle room due to low UV loss right now, it would sure come in handy if you miss an adjustment time or dial it down too far as you learn. I learned running 'hot' and it worked so well I never stopped.

 

[diesel1218]

Just finished reading this thread. I always love the transitions when someone learns how to manage their own pool! We all started in similar positions. Sounds like you got a great handle on testing and that you’re likely realizing you don’t necessarily need your pool tech.

Well I wouldn't say I know what I am doing yet but I am for sure getting more comfortable testing. I fired my second pool guy as soon as I ordered my TFProKit.

 

[kul]

The winter is a great time to start so you can be more comfortable once the summer is here. Best wishes!

 

[diesel1218]

50% of 6 hours is 3 hours on. 100% of 3 hours is 3 hours on. (Etc etc).

Amazing no one has been able to explain this not even the contract that came out to install the replacement today. I only needed him because I made them replace the fitting on my pipe due to them using wrenches to take it off. So I dont have mine on a schedule right now just on when the pool is on.

So by this are you saying .5 FC per hour at 100%? Meaning technically only needs to run two hours a day right now if my loss is about 1FC per day?

 

[diesel1218]

The winter is a great time to start so you can be more comfortable once the summer is here. Best wishes!

That you and yes I agree it will be more challenging during spring and summer but by then I should know what I am doing.

 

[diesel1218]

Ok so at 16k gallons it should produce about 1/2 FC per hour 'on'. At 15k gallons it's .45 per hour.

50% of 6 hours is 3 hours on. 100% of 3 hours is 3 hours on. (Etc etc).

That range is fine in the earrrrrrrrrly FL season right now as you aren't losing much FC per day. When the daily loss ramps up with the longer days and higher sun angle, you'll want to maintain the upper side of the range to allow some wiggle room. You could very well lose 5ppm a day in sunny FL mid season. If you're running a 5.5 you'd be below min with one afternoon's worth of SWG hiccup.

I caught mine shutting off for 12 hours due to reading low salt during/after big rains 7 or 8 times last sesson. 1 inch of rain is less than 1/60th of my pool, but if the pool isn't well mixed yet the cell might be testing mostly fresh water on top. This is particularly an issue for those that don't run 24/7. The pool kicks on hours after the storm and the SWG runs its self check with mostly fresh water. Then it shuts off until the next self check.

Although you technically don't need much wiggle room due to low UV loss right now, it would sure come in handy if you miss an adjustment time or dial it down too far as you learn. I learned running 'hot' and it worked so well I never stopped.

I think I get it now. My pool runs about 12 hours a day. (Do you recommended more?). SO at 12 hours a day that's the SWG working for 6 hours at 50% meaning it should produce 3FC by tomorrow.

 

[Newdude]

So by this are you saying .5 FC per hour at 100%?

Yes. At 100% it is producing when the pump is on. At 40% it is producing 40% of the time the pump is on, so 10 hours at 40% is really 4 hours 'on'. 2 hours on (however you want to math it) is all you need with a 1 FC daily loss right now. Monitor and adjust as necessary. We're not 100% on the volume so it may take some dialing in.

The UV loss will slowly but steadily increase until the mid season, then slowly fall for the back half of the season. It may hiccup at times and lose less or more than wad expected but for the most part it follows the general path. Think of a bell curve with little loss now and the fall and more in the middle. Your job is to match or slightly exceede loss, remaining free and clear away from min at all times.

Always factor your testing time as well. If you're testing after the SWG put the FC back, it will look great. If you test before it puts the FC back, it might look low. It's easy to see the higher # and think everything is great so be mindful of the possible swing because the high # may not be enough for that part of the season. (Like above at 5.5 FC when losing 5ppm a day). So either test at the low point of the day, or factor in what the low point may be.

Always remember the SWG takes the full run time to produce the days FC. If you're off by .5 FC, feel free to use the +/- on the cell to make it up. If you need a *now boost* then LC will get you there in minutes. Then let the cell maintain it once it's raised.

 

[Newdude]

My pool runs about 12 hours a day. (Do you recommended more?)

The pool needs to run to perform a function. Skimming / swg / heat / filter / water features / etc. Each of those functions has a min speed needed to work. Start low and increase RPMs by 100 until each works well, then note what speed you need and add 100 RPMs to account for lower flow as the filter gets dirty. The higher speeds cover the lower functions by default.

This time of year you likely have next to no debris blowing in and barely need any filtering and skimming. You could probably get away with the 2 hours needed for FC production. (with the cell at 100%) Once the pollen gets going (and in the fall) you'll need the most time filtering skimming that you will all season and the current 12 hours at low RPM is probably about right. Mid season you'll need somewhere in the middle.

I can't be bothered adjusting pump runtime and let it go 24/7 at low RPMs for $20 ish a month. The added bonus is I'm skimming and filtering around the clock. Even with 12 hours off, that's a long time for debris to get waterlogged and sink to the bottom.

The added added bonus is the SWG is producing around the clock also, always keeping me topped off. Then I only have to adjust the cell%, and not the cell% and the pump. Every little bit of less maths helps.

But yeah. 24/7 low speed with a SWG is only way to go IMO.