PSA : Rain and SWG

[VinnyinNJ]

@Newdude you were right on either the water needing more mixing or the tips. I cleaned the tips this morning and tested again and the salt was 2400... better than 1800! I'm going to check the long range forecast and if there's no rain forecasted I'm throwing my salt into the pool. I need to join that club!

 

[revitup]

I’m always amazed at the stories regarding rain dilution
Let’s just say you have a 15x30 pool, 5’ average depth. The capacity of that pool is 13,275 gallons. Now let’s say you had a huge 3” rainstorm. In a 15x30 rectangular pool, 1” is 280 gallons. 3” represents 840 gallons. 840 gallons is about 6.5% of the pool’s capacity.
All the chems in the pool are therefore diluted by 6.5%, including salt. How is that even measurable with a test whose margin of error is +/~ 200 at best?

 

[markayash]

I just got a energy use printout from our energy company, PSEG, and it told me I used $89 more electric this mid May/mid June than I did last year. Typically is shows we are about as energy efficient as the most energy efficient houses around our area.

We started our pool mid May, had in running 24/7 for a few weeks but it was also warmer and we go from heat to AC, very rarely do we open windows due to allergies. So a warmish day would have us turning on the AC. This report doesn't break out our various uses. I look at it as I bought the pool and I need to absorb the expenses of owning a pool so if it costs $90 a month in electric to own 4 months a year so be it. My electric bills typically aren't huge so no big deal for us.

I took the 330 watts my pump uses and estimated 150 watts for the SWG ( doesn’t run 24/7 since it set at 35% and says mine cost around $48 dollars a month.
I like that tool because I debate if I should drop my pump speed down and when I realize it’s maybe $2 a month difference I leave it

 

[Newdude]

I’m always amazed at the stories regarding rain dilution

I wholeheartedly agree. Buy Vinny has gotten over 20 inches this year in an aboveground that's 48 inches tall. Lol. Kinda makes a dent.

 

[VinnyinNJ]

I’m always amazed at the stories regarding rain dilution
Let’s just say you have a 15x30 pool, 5’ average depth. The capacity of that pool is 13,275 gallons. Now let’s say you had a huge 3” rainstorm. In a 15x30 rectangular pool, 1” is 280 gallons. 3” represents 840 gallons. 840 gallons is about 6.5% of the pool’s capacity.
All the chems in the pool are therefore diluted by 6.5%, including salt. How is that even measurable with a test whose margin of error is +/~ 200 at best?

To be honest and Newdude said, I think I underestimated how much rain we got since opening the pool. I had to lower my water by about 2 inches to get the water to the proper place for the skimmer. I was thinking free water but in actuality that skimmer lid just kept on oozing water 24/7 and when it rained it just kept on diluting the water and oozing water. 2 inches for my pool is about 560 gallons which is about 4.2% of the volume (@Newdude the pool is 52 inches not 48! ), since I did not drain the pool after the first amount of rain I don't know how many more inches/gallons my pool collected and oozed out. I'm now aware of this dilution and will make sure going forward to drain the pool to proper level and make note of it. I have not noticed dilution with other the chemistries but it could be I have been looking at and maintaining them vs the pool salt which I left because I wasn't using the SWG.

I would suspect if I was running my SWG that I would have noticed low salt happening either because of testing or my SWG indicating low salt.

 

[Newdude]

(@Newdude the pool is 52 inches not 48! ),

You know. Thus has been bugging me for a while and we are gonna settle it today. So THANKS.

On the 52's. Is that total wall, or water height ? Cuz in my head I'm thinking it's wall height per usual industry specs.

 

[VinnyinNJ]

You know. Thus has been bugging me for a while and we are gonna settle it today. So THANKS.

On the 52's. Is that total wall, or water height ? Cuz in my head I'm thinking it's wall height per usual industry specs.

It's 52 " wall height so probably 48" water height, so a 48" wall height is probably 44" water height. When I had the water up to top of skimmer I was probably at 50 inch water height ... I was living large!

 

[VinnyinNJ]

@Newdude I know I kind of hijacked your thread, sorry about that! I think your PSA is important given that some people (me) would have no clue about effects of rain on their pool chemistries. It makes sense a lot of rain will affect everything and in the case of a SWG needing a certain amount of salt to operate or it turns itself off. And that rain water will sit on top of the salted water so the SWG may turn itself off temporarily until the pool water mixes with the rain water in the case of not too much dilution.

 

[markayash]

I was reading and salt water is heavier then fresh rain water

https://spaceplace.nasa.gov/ocean-currents/en/saltwedge.en.png

 

[Newdude]

I know I kind of hijacked your thread, sorry

Nope. My thread my rules. Anything even remotely relevant is fair game. Or dogs.


And your points were all related to mine, so.

 

[Animal827]

I am confused as to how salt would diminish that much over a season. I opened the pool in early May and got my salt to 4000 (added one extra bag cause I miscalculated how long it takes for salt to fully dissolve). It has been a steady 3800 since June. We have had a lot of rainfall here in the northeast and I feel like I am adding several inches of water each week due to splashout and waterfalls. I suspect that in Aigust it may get to 3600, which would be ideal for me...but to lose thousamds of ppm of salt sounds weird.

 

[dleonard1122]

I've admittedly never ventured into The Deep End but doesn't some of the salt get used up by the SWG during the chlorine generating process? From what I remember from HS chemistry salt was NaCl, and I always just kind of assumed some of that Cl was getting pulled to make chlorine.

 

[markayash]

I've admittedly never ventured into The Deep End but doesn't some of the salt get used up by the SWG during the chlorine generating process? From what I remember from HS chemistry salt was NaCl, and I always just kind of assumed some of that Cl was getting pulled to make chlorine.

That’s what I wonder but everyone says no it won’t

 

[kellyfair]

Nope, salt isn’t used up in the process - the end result is basically chlorine gas and salt, so it goes right back into the water.

Those who have sand filters lose salt when they backwash.

 

[Newdude]

I am confused as to how salt would diminish that much over a season

That's exactly it. Short term it's all but unnoticeable but over the season, (and the off season with a mesh cover or no cover) it adds up.

While awaiting further confirmation, it appears the screwy test results were mostly bottle related with messed up drops. We're all only as good as the test results tell us.