New house with pool and new member here :)

[david6768]

Hello, I bought a house with an indoor saltwater pool. When I bought the house the liner was torn, pump motor burned out, filter leaked sand into the pool. I had the liner replaced first and as the pump and SWG wasn't working I added 4 gallons of 6% bleach into the 36000 gallon pool ( 20 X40 3ft shallow end 9ft deep end = 36000 gallons my math??) a few weeks later the contracter came out and replaced the pump and the filter. I tested the chlorine with my Walmart aqua pool test kit and it showed I was over 5ppm but I wasn't too concerned as the 4 gallons of bleach should have brought me up to plus or minus 5ppm according to my calculations. I added whatever amount of salt, I don't remember off the top of my head it was last year but I believe like 16 bags if I remember correctly. This was in November and I am in West Tennesee so once I got the broken stuff fixed I closed the pool for the year. The pool has a propane heater and the timer will kick everything on if the outside temp drops below 40 degrees. The equipment is outdoors, I set the pool house temp to 60 degrees and left for the year.

The problem I am having is when I tested the PH it showed 8.4+ so I gradually added a gallon of muratic acid, the next morning the ph still showed 8.4 so I added another this went on for 4 days and 4 gallons of muratic acid , the reading never dropped. I felt something was funny so I jumped on the net and found your forum. I did some reading here and found out that high chlorine levels will skew the PH so now I am worried that I have an actual PH of like 2 or something and I am going to be swimming in battery acid. I read a thread that suggested to get a glass of pool water out into the sun to burn off the chlorine then retest for PH. I tested the water every couple of hours until the chlorine test showed 0 then tested the PH and got a ph of 7.6 ideal so good to go there and my worst fears are abated. My TF100 came in the mail today and I wanted to find out my chlorine level so I did the DPD test and came up with 62 drops/31 ppm I had my wife try it and she got 58 drops/28ppm. I have only added the 4 gallons of bleach in November of last year and the SWG is set to 1% output as I didn't want to add much if my chlorine was already high according to my Walmart test kit I figured 1% wouldn't even keep up with the daily loss. Somehow I now have 30ppm chlorine!! I am not using any stablizer at all so I am wondering if I am ok? Some of the shock levels listed show up to 39 ppm and I am only at 30. Am at a dangerous level of chlorine? Should I get some chlorine reducer? Should just add some stablizer to buffer the chlorine and I'll be ok? How the heck did I get up to 30ppm from just adding 4 gallons of bleach unless I have a runaway SWG? If you have made it this far, thank you for taking the time to read this, I know it was long but I wanted to make sure all the facts were included to get the best advice



20 x 40 saltwater indoor inground pool
3900 ppm salt
Hayward aquarite SWG
4 gallons of plain walmart unscented bleach
4 gallons muratic acid
16 40lb bags of salt ( I think, exact number I had calculated out last year, added it in, got the salt right and forgot
TF100 chlorine dpd test showing 30ppm clorine 2 ppm CC
120 TA
PH still showing 8.4 due to high chlorine level but showing 7.6 on a sample left out in the sun 8 hours to burn off the chlorine
zero cyanuric acid (buffer added)

 

[JasonLion]

Welcome to TFP!

It all depends what your CYA level is. You can't actually have a stabilizer/CYA level of anything anywhere near zero. With CYA near zero you would lose all of your chlorine to sunlight in a few hours and the SWG would never be able to keep up with the chlorine loss. On the other hand, is this pool indoors, or covered, or have any kind of sun shade?

Very high (>20) FC levels do completely throw off the PH test, and cause it to read very high regardless of what the actual PH is. So your PH results support the idea that FC is >20.

 

[david6768]

Thank you for the help,
Yes the pool is indoors and my CYA level is zero as none has been added since the pool was filled. the only things added have been bleach, muratic acid, salt and water. From what I have read CYA is like sunscreen for chlorine and unnecessary in an indoor pool that gets no sun. Still I only put 4 gallons of bleach in and the SWG is set on 1% on time so unless it is faulty and running away I can't see how I got 30 PPM Chlorine and I am wondering if it is safe to swim in at those levels. The water is crystal clear, but at 30 ppm I probably could throw a dead body in there and it wouldn't cloud up!
the water doesn't hurt my eyes or anything which I assume it would at 30 ppm

 

[duraleigh]

Indoors ays it all. Only two things consume chlorine in a pool.....organics in the water and sunlight. The sunlight was never a factor and you quickly killed any organics so now there is nothing to consume the chlorine and the SWG continues to put it out. Shut it off.

There is a suggested 20ppm level of CYA even for an indoor pool. You should raise your CYA to that level and let the chlorine continue to come down until it gets about 2-3ppm.

Posting a complete set of test results would be very helpful.

 

[david6768]

PH 7.6 I had to sit a jar of pool water in the sun for 6 hours to burn off the chlorine to get this reading, if there is a better way to get rid of the chlorine and not skew the test I'm all ears.
FC 30
CC 1 no CYA so it's all FC
CYA test I didn't do because I know it's zero
TA 120
Calcium hardness test I haven't done yet


The SWG has been off for a while and when it was on it was only on at 1%, I know chlorine gets burned off by the sun but shouldn't I have some daily loss in an indoor pool?


So you are saying to add CYA to 20ppm then that would lock up 20ppm chlorine then I should have FC of 10ppm and let that burn off until I get the desired 2 ppm? The recomended level I found by my research was 0-20 ppm CYA at one website and another website said absolutly do not add CYA to an indoor pool. What is the benefit of adding CYA to an indoor pool? I am not trying to argue the advice or anything please don't take it that way, I just want to learn the whys so I better understand what I am doing.

 

[JasonLion]

You should not swim when FC is above 5 and there isn't any CYA in the water. Adding just a little CYA will bring the active chlorine level down dramatically and make it swimmable again, or you can lower the FC level with chemicals.

CYA doesn't change the FC levels that you measure with the test kit. It changes the percentage of the FC that is actually active at any given moment. Hum, I hope that isn't too confusing.

 

[david6768]

not confusing at all, thank you for the help
so I am just adding the CYA to sequester the Chlorine, that why I was assuming he suggested it but assuming is all bad

 

[JasonLion]

Relatively low CYA levels serve several purposes in an indoor pool. They allow the FC level to be a little on the high side without the bad side effects you get when there is no CYA (metal corrosion, hair breaking off, itchy skin). CYA switches the way organic debris reacts with chlorine so fewer of the "bad" forms of CC are produced, so there isn't as much of an air quality issue as there might otherwise be. And so on.