TA, CH, and CYA questions for SWG plaster pool

[Taylor1584]

Using the pool calc. and Test Kit 100, SWG
Ph 7.5
FC 6
TA 100
CH 400
CYA 90
Salt 2740
Borate 15 I have not added any, just what water tests
CSI -.22

I have very hard water for fill. Lots of build up on blue glazed tile waterline. At the start CYA was 20, and CH was 450+. I drain some and add water frequently. I am not sure how to bring the calcium hardness down, it's in the fill water. Using the calculator I brought the CYA up, used less that calculator recommended and went past 80. I see a slight yellowish brown green tinge on the sides, I brush and some goes away. I did follow the shock steps as recommended here and sides improved somewhat but appears tinged. I brought up the CYA to help the ph as pool has full sun (Houston) and water up till now has been warm. Should I start BBB now, or do you have recommendations. Sorry I jumped around just not sure of the order to make corrections. The test kit and calculator are great hand holders.
Thanks, Chris

 

[jblizzle]

Your CH is really not very high ... if you keep the pH in check, then you should not be getting scaling. The ring around the tile seems to be almost unavoidable, it is not really "scaling" per se, but more a result of water evaporating and leaving the deposits behind ... like you get in toilets, etc. Keeping the CSI negative can reduce this, but I don't think it will eliminate it.

What do you mean by switching to BBB? All that means is that you understand your pools chemistry and only add the chemicals that it needs ... it does not really mean you have to use bleach, baking soda and borax.

If you are continuing to see algae, then it seems like the shock process was not completed or the FC was allowed to drop too low again. Does it appear only in the shadow parts of the pool? That could mean mustard algae, which is a little more tricky, but there is an article in Pool School on how to treat it.

 

[Richard320]

That CH is not too bad for Texas.

If you've got something growing on the walls, you likely need to perform the Shock Process. And with CYA as high as you say, that's going to be difficult. You might wish to repeat the CYA test - read, pour it back in, repeat, a few times to be sure of your reading. Then head to Pool School and study up on performing the overnight loss test and the shock process. Link's in the upper right.

 

[Melt In The Sun]

Sounds like you've had a bit of algae? First thing to do is be sure it's gone...have you run the overnight chlorine loss test? That will tell you if you still need to be shocking.

As for the CH, there's nothing you can do but manage it. Play with the pH, TA, and CH numbers in the pool calculator, and you'll see about where you need to maintain your numbers to not have scale forming in the pool (CSI neutral-ish). As for the water line, some scale will always form there...at least I haven't been able to stop it no matter how closely I've watched the chemistry.

 

[HouTex]

I'm in Houston as well, and I've just gotten used to high CH. It is always between 400 and 500 depending on how much rain we've had. During my first year (2011) during the SE Texas drought I partially drained and refilled a couple of times because I felt like the CH was getting too high. This year it has stayed under 500 so I'm not worried about it.

Not sure how long you've had your pool and whether your pH is stable. My pool is about 2 years old and my pH still rises due to the SWG, the spill over spa, and a large pump. But other than adding some stabilizer and salt from time to time, about the only thing I need to add is MA about every 4-7 days.

When you get the CYA at the right amount and kill the algae (if that's what it was) through the shock method recommended here, just keep your CL at the recommended levels and you shouldn't have a problem. I've followed the good advice given here and I've yet to have a cloudy or green pool.

 

[UnderWaterVanya]

Shock process first... Then everything else.

BTW why did you add CYA to help with pH? Lower your pH with muratic acid and let the TA drift down some to reduce pH rise if you are fighting that.

Sent via Tapatalk...

 

[bobodaclown]

I have a SWCG and my CH is around 500, I always run a negative CSI. No Scaling and water looks great.

 

[Taylor1584]

Thanks everyone for the advice. The reason I posted the question in the first place was the algae?? or whatever was making the pool walls unsightly. Water is beautiful. Also, I was checking ph daily and was having to add MA daily. I originally had water tested at Pool Store and the results over time indicated almost nonexistant CYA. And ph kept going up daily. In my research I found you all and order the 100 test kit. The store guys weren't too far off, several of the "kids" doing the water testing were intending on majoring in chemistry, so they actually tried to work accurately. But the store still sells and sells and sells. After becoming more skilled with testing, I am a long way from H.S. chem where I did get an A, anyway, I read all of pool school and reread many parts. So now I wanted to get my numbers to look good, the pool to look good. So I added CYA after checking and double checking my numbers and getting water tested 2 other places. I am a chicken so I added only part of what was needed, powered in a tube sock at a skimmer with pump going. As per advice here, I have added ordinary bleach, using the pool calcluator, checking every hour for several hours to get it to shock level. I used the CYA/Chlorine chart. My pool's CYA is 90, SWG here, so I targeted 32, since 90 was not on the chart. It did take 3 rounds of adding bleach over a few hours, I didn't want to disinfect the slough behind our yard, but eventually got there. I resumed testing in the morning, ph is hovering at ph 7.2-7.4 and chlorine is at 38. My pool man (the mister) is doing the brushing. I am bribing with beer and BBQ. So that's where it stands. How long does the chlorine need to stay this high. Do I just keep brushing? Does the chlorine waft down to normal, how long does that take. Do I need to keep checking ph, I am anyway, but question adding at same time as chlorine. I have been adding one, waiting an hour, pump is running 24/7, and then add the other. Please if I need to do anything else or stop doing something before I hurt my pool please chime in. Oh, sorry for the time delay from original. Someone hit my car and totaled it. No injuries, just aggravation. Thanks.

 

[Richard320]

Thanks everyone for the advice. The reason I posted the question in the first place was the algae?? or whatever was making the pool walls unsightly. Water is beautiful. Also, I was checking ph daily and was having to add MA daily. I originally had water tested at Pool Store and the results over time indicated almost nonexistant CYA. And ph kept going up daily. In my research I found you all and order the 100 test kit. The store guys weren't too far off, several of the "kids" doing the water testing were intending on majoring in chemistry, so they actually tried to work accurately. But the store still sells and sells and sells. After becoming more skilled with testing, I am a long way from H.S. chem where I did get an A, anyway, I read all of pool school and reread many parts. So now I wanted to get my numbers to look good, the pool to look good. So I added CYA after checking and double checking my numbers and getting water tested 2 other places. I am a chicken so I added only part of what was needed, powered in a tube sock at a skimmer with pump going. As per advice here, I have added ordinary bleach, using the pool calcluator, checking every hour for several hours to get it to shock level. I used the CYA/Chlorine chart. My pool's CYA is 90, SWG here, so I targeted 32, since 90 was not on the chart. It did take 3 rounds of adding bleach over a few hours, I didn't want to disinfect the slough behind our yard, but eventually got there. I resumed testing in the morning, ph is hovering at ph 7.2-7.4 and chlorine is at 38. My pool man (the mister) is doing the brushing. I am bribing with beer and BBQ. So that's where it stands. How long does the chlorine need to stay this high. Do I just keep brushing? Does the chlorine waft down to normal, how long does that take. Do I need to keep checking ph, I am anyway, but question adding at same time as chlorine. I have been adding one, waiting an hour, pump is running 24/7, and then add the other. Please if I need to do anything else or stop doing something before I hurt my pool please chime in. Oh, sorry for the time delay from original. Someone hit my car and totaled it. No injuries, just aggravation. Thanks.

You need to read the article on the shock process, for starters.

First, pH reading is inaccurate when FC is above 10. So ignore pH. We always advise getting it set first, and then ignoring it until the process is complete.

Secondly, you know you're done, and can let the FC drop, when
1) The water is clear - the walls, too.
2) CC is .5 or less
3) The overnight drop is less than 1 ppm. That means taking a reading in the evening, when it's well mixed and the sun is no longer on the pool, and comparing it to an early morning reading taken before the sun hits it. If it holds, and the other two conditions are met, you're done.

Finally, and it's too late now, but we advise setting CYA to about 30 when performing the shock process because you don't need to raise FC so high. Then when it's done, you can always add more CYA. But I'll put it in here in case someone is browsing and stumbles across this thread.

 

[Taylor1584]

Richard,

First, pH reading is inaccurate when FC is above 10. So ignore pH. We always advise getting it set first, and then ignoring it until the process is complete.

Secondly, you know you're done, and can let the FC drop, when
1) The water is clear - the walls, too.
2) CC is .5 or less
3) The overnight drop is less than 1 ppm. That means taking a reading in the evening, when it's well mixed and the sun is no longer on the pool, and comparing it to an early morning reading taken before the sun hits it. If it holds, and the other two conditions are met, you're done.

Finally, and it's too late now, but we advise setting CYA to about 30 when performing the shock process because you don't need to raise FC so high. Then when it's done, you can always add more CYA. But I'll put it in here in case someone is browsing and stumbles across this thread.

Thanks, I am trying to follow the shock instructions, which I have and am reading. I did notice that I was the get the ph at 7.2 before shocking which I did. I guessed I missed where I was to lower the CYA since mine had been so low before. I realize it then took more chlorine to get to shock lever. My CC is .5 or less I have been recording my results on a spreadsheet so I can see where I've been and CC has never been above .5. After dinner and the morning will check FC again.. Thanks for the advice.

 

[Taylor1584]

Opps, sorry Richard,

I cut and pasted so I could address your advice, and hit submit to fast. Hope you can figure out what is yours and my comments. Just checked chlorine still the same, checking in the morning. Again, thanks to you all, otherwise I would just let it go. Baby steps.

 

[Taylor1584]

Well, just checked chlorine, same as last night,. Water is clear, sparkly, I still see tinges of stain on the walls. Will be brushing again shortly. Question, I know you said process was done when overnight FC loss test was 0, if the sides are not clear should I keep the process going if the chlorine slips during the day in full sunlight?

 

[Richard320]

Well, just checked chlorine, same as last night,. Water is clear, sparkly, I still see tinges of stain on the walls. Will be brushing again shortly. Question, I know you said process was done when overnight FC loss test was 0, if the sides are not clear should I keep the process going if the chlorine slips during the day in full sunlight?

Yep. You want to kill all the algae before it can reproduce.