SWG not keeping Chlorine up though levels are correct

[slopland]

Hey all,
I have a 7,500 gallon above ground pool. I have gotten and maintained all levels to the appropriate level. I run the pump (Intex 3,500 GPH sand filter) 10 hours a day and the SWG around 8 hours a day. My salt level is appropriate and I have not gotten any errors from the SWG. My CYA is around 50 consistantly, my PH is a little basic at 8.4 most days, I bring it down with PH reducer. I seem to have to do this at least once a week (2 cups of PH reducer). The biggest problem is that my Chlorine level drops about every 3 days and I have to add bleach. Even though my levels are good, my CYA is 50, my SWG runs 8 hours a day, I have no errors, the chlorine will not maintain.

What am I missing?

Thanks in advance.
Slop

 

[PAGirl]

With an SWG, it's usually recommended that you run a higher CYA, along with the fact you are in a pretty warm climate. You could bump it up to 70 and see if that helps. I would recommend doing an Pool School - Perform the Overnight FC Loss Test (OCLT) OCLT first, to see if a SLAM is necessary. I can say, though, I'm not sure about the run time for the SWG, someone with more knowledge about that aspect maybe more helpful.

 

[Jimrahbe]

slop,

If your SWCG will not keep up you have to increase your run time.. or adjust the % of output which you might not have.

Pools use 2 to 4 ppm of FC (chlorine) each day. You have to look in your manual and see how much chlorine you SWCG is capable of making so that you can determine how long you need to run your SWCG. My guess is that 8 hours is not near enough with a little cell.

I also agree that one way to reduce chlorine loss is to increase your CYA (Stabilizer) to 70 or 80 ppm.

Thanks for posting,

Jim R.

 

[slopland]

Sorry for the delay, the responses are much appreciated. I will do both of those this week and see what happens. Thanks a lot! I'll post the results soon.

 

[slopland]

I have tried the above. The CYA is around 90 ppm, I am running the SWG 10 hours a day with the pump. I lose about 2ppm of chlorine a day and my PH requires acid every 2-3 days to keep the PH around 7. It seems that the chlorine goes down and PH goes up every couple of days. It doesn't seem like my SWG is doing anything. Recommended run time for a 7,500 gallon pool is 6 hours per day. ..I'm not sure what to do.

 

[JoeGolan]

I have tried the above. The CYA is around 90 ppm, I am running the SWG 10 hours a day with the pump. I lose about 2ppm of chlorine a day and my PH requires acid every 2-3 days to keep the PH around 7. It seems that the chlorine goes down and PH goes up every couple of days. It doesn't seem like my SWG is doing anything. Recommended run time for a 7,500 gallon pool is 6 hours per day. ..I'm not sure what to do.

What SWG do you have?

What is it set to % wise?

How old is the cell?

Do you have any diagnostics on the SWG controller? Results?

 

[OLDWAYS]

If your salt is at 3000 , PH is in range( salt water systems are always higher) , and alka & cyanuric acid are close HIT THE BOOST BUTTON to shock the pool. If the pool is used a lot shock weekly with trichloro-s-triazinetrione or sodium dichloro-s-triazinetrione dihydrate. But use the boost button first I have to boost our 12,000 gallons every time the boy and his crew get wet ( they are monsters ) . If you are set to run 9 hours when you boost the pool it will run for 72 hours before it goes back to regular timed mode unless you turn the system off.

 

[cfherrman]

If your salt is at 3000 , PH is in range( salt water systems are always higher) , and alka & cyanuric acid are close HIT THE BOOST BUTTON to shock the pool. If the pool is used a lot shock weekly with trichloro-s-triazinetrione or sodium dichloro-s-triazinetrione dihydrate. But use the boost button first I have to boost our 12,000 gallons every time the boy and his crew get wet ( they are monsters ) . If you are set to run 9 hours when you boost the pool it will run for 72 hours before it goes back to regular timed mode unless you turn the system off.

Sounds like guess work and not tfpc. Instead of guessing you have a problem, perform a oclt and know if you have one or not.

Further information on your equipment will get the figuring out process going to fix the problem.

Labels and recommendations from pool stuff follow incorrect guidelines and ignore the last 40 years of science, I'm guessing the 6 hours a day run time is to get 1-3 ppm clorine, you need higher with 90 cya.

 

[OLDWAYS]

I agree , my INTEX CS7111 SALT WATER GEN.'s manual has 7000 gallon run time @9 hours. We have 12,000+ gallons and run ours 14-16 hours a day with semi regular boost time to shock after heavy use. 2-3 times a season we have to give it a shock with 1 pound of
SODIUM DICHLORO-S-TRIAZINETRIONE DIHYDRATE. OUR unit's listed sanitizer output is 5 grams/hour. I maintain a cyanuric acid level at 35-40 a level of 90 sounds high

 

[PAGirl]

Y

I agree , my INTEX CS7111 SALT WATER GEN.'s manual has 7000 gallon run time @9 hours. We have 12,000+ gallons and run ours 14-16 hours a day with semi regular boost time to shock after heavy use. 2-3 times a season we have to give it a shock with 1 pound of
SODIUM DICHLORO-S-TRIAZINETRIONE DIHYDRATE. OUR unit's listed sanitizer output is 5 grams/hour. I maintain a cyanuric acid level at 35-40 a level of 90 sounds high

Have you read Pool School yet? TFP has recommendation that are different that the "norm" based on science.

Pool School - Pool Chemistry

 

[Jimrahbe]

Slop,

I suggest you let your pH sit at 7.8 for a long as possible... not sure what your target is, but anything less than 7.6 is too low for most SWCG pools..

Thanks,

Jim R.

 

[slopland]

I have read TFP. I have tried the things on here. If my PH gets to basic, I end up with white build up on the SWG electrodes so I keep it low. I have been running my SWG for 10 hours a day and it seems like nothing is working. Salt level is where it needs to be, CYA is 70ppm: I get my chlorine to around 2.8ppm and within two days it is back down to 0.5ppm. I end up adding liquid chlorine again..It is like the SWG is not working. I have switched out the electrodes to a new set, but the same problem continues. I appreciate the replies and suggestions.

Is it possible I'm using the wrong type of salt? I used pool salt from walmart...With the recommended % that the manual asked for.

 

[KarenNJ]

did you do the overnight test (OCLT)? Maybe you have something eating up all your chlorine. I would start with that so you know for sure.