Chemicals got off in just a few days absence

[Rick1970]

Hi all,

First time post here looking to gain some assistance. We have an Intex above ground pool, 22 feet by 52 inches deep, roughly 10500 gallons of water with a salt water system. We purchased this unit last year and did well most of our swimming season here in Southern Iowa.

Got it up earlier this year than last, kids got in before Memorial Day this year, and it has been quite hot here the last 3 weeks (in the 90's almost everyday). We were gone for about 4 days and in that time our chemicals started getting out of whack. I have a TF-100 test kit, bought at the recommendations of this site last year, and have been doing well with frequent checks and getting fairly solid results. However, when I checked them tonight here is what we currently have for numbers:

ph 7.2 (had been right at 7.5)
chlorine went from right round 2/4 ppm to non existent tonight
calcium is running around 175 ppm
alkalinity has maintained a level of 40
CYA took a dive to 30 from 50
salt level dropped to 2800 from 3200

I don't want to over react with things and create any new issues, but certainly want to stay on top of things to make sure we don't have anything major start to take over our pool either. My son thinks it appeared like that there might have been some staining on the sides of our pool tonight, but my eyesight didn't detect that, although admittedly his eyesight is better than mine.

Thoughts and suggestions would be greatly appreciated.


Rick

 

[aussieta]

welcome to TFP
at the top of the page is a link to pool school which will be of help to you
your ph may be low as your ta is also low
cya and salt would be within the +/- error for the test
as your chlorine has dropped below minimum you will need to perform a slam
get some chlorine in there asap
long term maybe a bit of bicarbonate soda to raise ph and ta

 

[domct203]

Hi all,

First time post here looking to gain some assistance. We have an Intex above ground pool, 22 feet by 52 inches deep, roughly 10500 gallons of water with a salt water system. We purchased this unit last year and did well most of our swimming season here in Southern Iowa.

Got it up earlier this year than last, kids got in before Memorial Day this year, and it has been quite hot here the last 3 weeks (in the 90's almost everyday). We were gone for about 4 days and in that time our chemicals started getting out of whack. I have a TF-100 test kit, bought at the recommendations of this site last year, and have been doing well with frequent checks and getting fairly solid results. However, when I checked them tonight here is what we currently have for numbers:

ph 7.2 (had been right at 7.5)
chlorine went from right round 2/4 ppm to non existent tonight
calcium is running around 175 ppm
alkalinity has maintained a level of 40
CYA took a dive to 30 from 50
salt level dropped to 2800 from 3200

I don't want to over react with things and create any new issues, but certainly want to stay on top of things to make sure we don't have anything major start to take over our pool either. My son thinks it appeared like that there might have been some staining on the sides of our pool tonight, but my eyesight didn't detect that, although admittedly his eyesight is better than mine.

Thoughts and suggestions would be greatly appreciated.


Rick

Welcome.

If your SWG cannot keep up with the FC demand it is either the sun burning it off or you have caught the beginning of an algae bloom. You should supplement with liquid chlorine as we determine what is going on. If your FC has been down around 2ppm you have been below your minimum FC value for your CYA (at 50ppm CYA your absolute minimum FC level is 2.5ppm with a SWG) you most likely allowed algae to take hold.

Perform the OCLT to determine if this is something organic. Be sure to shut down the SWG for the OCLT.

http://www.troublefreepool.com/content/136-perform-the-overnight-fc-chlorine-loss-test-oclt

If you do not pass the OCLT you will need to SLAM the pool.

http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

Dom

 

[bmoreswim]

The main takeaway here is that your pool does need regular testing and then related chemical/automation adjustments. Regular testing generally means daily or every other day if things are dialed in. Going away for a few days really isn't possible. JK! It just takes some pre-planning and really being aware of your pool's needs.
FC is a consumable and needs to be replenished which your SWG is doing. Adjusting the % output or pump runtime will affect the amount of chlorine produced.
pH will tend to increase when using a SWG. Yours did not but there are other things that could affect it. But just keep logging your testing in a notebook so you always have a reference for future situations.

 

[Rick1970]

Thanks everybody for your input. I added alkalinity increaser about 12:00 and have some chlorine to add as well. Give that a start and see where we go from there.

Rick

 

[Mr Bruce]

You would have been better off getting chlorine in there immediately. TA is the last thing you need to worry about. Also, if you are buying something called "Alkalinity Increaser" you are paying for very expensive baking soda which you can get at the grocery store.

 

[Rick1970]

Thanks Mr. Bruce. I just happened to have the alkalinity increaser on hand and it was something I was told by a friend to keep on hand. I actually didn't pay too much for it and price wise was about the same as the baking soda and got it all in one pail versus several boxes for the same amount. I went out and got chlorine today and have added some according to the calculator numbers and will check them tonight to see how we are doing. Once again thanks for all of the help everyone.

Rick

 

[domct203]

Thanks Mr. Bruce. I just happened to have the alkalinity increaser on hand and it was something I was told by a friend to keep on hand. I actually didn't pay too much for it and price wise was about the same as the baking soda and got it all in one pail versus several boxes for the same amount. I went out and got chlorine today and have added some according to the calculator numbers and will check them tonight to see how we are doing. Once again thanks for all of the help everyone.

Rick

Have you performed an OCLT to make sure algae is not starting to grow from the low FC levels?

Dom