New to TFP - water balance issues

[ATX61]

First time poster here. Recently joined TFP and have been reading throughout the forums and also Pool School. I will be installing a Hayward 400,000 BTU gas heater soon and want to get my water into good balance prior. Like a previous poster in this forum I had a pool service that was taking care of the pool when I bought the house 6 months ago. After reading up on pool maintenance I figured out the pool service didn't know what they were doing (using pucks in skimmer/exclusively test strips) so I decided to take over the maintenance and save $185/month. Bought a Taylor K-2006 kit and here are my results.

FC 13
pH 7.6
TA 100
CH 380
CYA 150+++++ off the charts
Cl2 6

I have ditched the pucks and using liquid chlorine now. So I realize I will need to drain some water to lower CYA. I am going to do the exchange method using a submersible pump and drain into sewer system clean out. The city requires a permit to drain into the sewer system and due to COVID permit requests are taking longer. In the meantime should I work to lower TA with addition of MA and aerate to raise pH? Any other tips based on my results are welcome.

 

[Dirk]

Hi and welcome to TFP. So glad you've decided to ditch the pool dope guy and take over the pool. You'll be so glad you did, too. You might do a suite of tests on your fill water and post those, which will help our water chemistry experts better advise you about the TA. You don't have to do the full suite, just pH, TA and CH.

What is "Cl2 6"? I don't recognize that.

 

[Texas Splash]

Welcome to TFP! Great job on the testing with a good kit. So you know the CYA is high, so that should be priority #1. No sense trying to adjust other things when that water will go out to the sewer. Once you get the CYA down to earth, ideally around 50 or so should be fine, then you can re-balance everything. Temps will begin to drop soon, so pool care will get much simpler soon.

 

[wireform]

Hasn't been mentioned, do a diluted cya test to see where the cya really is at then you can do your calculations at X gallons per hour exchange/% of pool. If you stop too soon and the water mixes you'll need to pump out fresh water again to achieve the same results. You need to know all this before you do the exchange then go a bit past just to be sure. You wouldn't know how low it got before the pump mixes the water for a couple of hours and then test for the results.

 

[Dirk]

The directions for the diluted cya test are on this page (see #8):

CYA - Cyanuric Acid Test

Cyanuric Acid (CYA) is the chemical name for what is commonly referred to as Stabilizer … Read more…

www.troublefreepool.com

 

[Jimrahbe]

61,

Not sure about your water rates, but I can replace all of my 17K pool for less than $75 bucks.. Just does not make much sense to not just drain most of the pool and start over..

Thanks,

Jim R.

 

[ATX61]

Hi and welcome to TFP. So glad you've decided to ditch the pool dope guy and take over the pool. You'll be so glad you did, too. You might do a suite of tests on your fill water and post those, which will help our water chemistry experts better advise you about the TA. You don't have to do the full suite, just pH, TA and CH.

What is "Cl2 6"? I don't recognize that.

Hi Dirk, thanks for the response. Cl2 is the abbreviation I saw somewhere being used for combined chlorine. I think I have seen it abbreviated as CC also. Let me know what is correct in discussing on the forum.

 

[ATX61]

61,

Not sure about your water rates, but I can replace all of my 17K pool for less than $75 bucks.. Just does not make much sense to not just drain most of the pool and start over..

Thanks,

Jim R.

Looks like water rates are much higher here in Austin. Based on most recent bill I figure that it will cost $12.75 per 1,000 gallons accounting for usage, waste water services and fees. At less than a couple hundred dollars that may be the way to go.

 

[Stoopalini]

Hi Dirk, thanks for the response. Cl2 is the abbreviation I saw somewhere being used for combined chlorine. I think I have seen it abbreviated as CC also. Let me know what is correct in discussing on the forum.

Cl2 is the chemical formula designation for a molecule of Chlorine. CC is what you want to use for Combined Chloramines.

"Chloramines, also known as combined chlorine, are formed when free chlorine reacts with ammonia like compounds called amines. Chloramines are poor disinfectants and greatly reduce the disinfection power of free chlorine, irritate mucous membranes, cause eye stinging and red eyes and irritate respiratory systems. "

Looks like water rates are much higher here in Austin. Based on most recent bill I figure that it will cost $12.75 per 1,000 gallons accounting for usage, waste water services and fees. At less than a couple hundred dollars that may be the way to go.

You may call the water department and ask about pool filling. Many will waive the waste water disposal fees for the amount of water, when filling a pool.

Up here in Liberty Hill, with Georgetown Water Coop, it cost me under $50 to fill my 14k gallon pool.

 

[Jimrahbe]

61,

Here is Bedford it is the same.. The City will waive the sewer service fee for the water used to fill a pool. Your City may not do the same, but it would make sense to find out first.. Also, in some cities, the water rate for the year is based upon usage in a certain month or couple of months.. You don't want to be filling a pool during those months.

Thanks,

Jim R.

 

[Dirk]

Hi Dirk, thanks for the response. Cl2 is the abbreviation I saw somewhere being used for combined chlorine. I think I have seen it abbreviated as CC also. Let me know what is correct in discussing on the forum.

We use CC, and we like to see it right below the FC, so:
FC 13
CC ?
pH 7.6
TA 100
CH 380
CYA 150+++++ off the charts

You didn't actually measure a CC of 6 did you? That's could be bad. But as per others, do the water exchange first before you deal with the rest of the water issues.

 

[ATX61]

We use CC, and we like to see it right below the FC, so:
FC 13
CC ?
pH 7.6
TA 100
CH 380
CYA 150+++++ off the charts

You didn't actually measure a CC of 6 did you? That's could be bad. But as per others, do the water exchange first before you deal with the rest of the water issues.

Looking back at my scribble I may have written that down incorrectly.

 

[ATX61]

61,

Here is Bedford it is the same.. The City will waive the sewer service fee for the water used to fill a pool. Your City may not do the same, but it would make sense to find out first.. Also, in some cities, the water rate for the year is based upon usage in a certain month or couple of months.. You don't want to be filling a pool during those months.

Thanks,

Jim R.

Just got off the phone with City of Austin. $175 for the permit and no option to have it waived. They want their cake and eat it too. If they catch you dumping into sewer system without permit or into storm drain (not allowed unless you dechlorinate and no algae) it is a $2,000 fine. Good tip on checking on when water usages rates are calculated. I'll be looking into that.

 

[Dirk]

Ah, another gov revenue stream (literally in this case)! Well, better to know in advance...

 

[ATX61]

Hi and welcome to TFP. So glad you've decided to ditch the pool dope guy and take over the pool. You'll be so glad you did, too. You might do a suite of tests on your fill water and post those, which will help our water chemistry experts better advise you about the TA. You don't have to do the full suite, just pH, TA and CH.

What is "Cl2 6"? I don't recognize that.

Here are the test results for tap/fill water

pH - 8.0+
TA - 70
CH - 60

 

[Dirk]

I don't know that "took 6 drops of reagent to lower to 7.2" means. Perhaps you're using the acid demand reagents? I never have, so can't advise on that. It doesn't matter for fill water. Your TA and CH are about as good as one can hope for for fill water. I don't see any special considerations there. Go ahead and exchange the water to bring the CYA down. Are you clear on the risks and your options for how to do that? And the instructions and steps? If not, ask away...

 

[ATX61]

Hasn't been mentioned, do a diluted cya test to see where the cya really is at then you can do your calculations at X gallons per hour exchange/% of pool. If you stop too soon and the water mixes you'll need to pump out fresh water again to achieve the same results. You need to know all this before you do the exchange then go a bit past just to be sure. You wouldn't know how low it got before the pump mixes the water for a couple of hours and then test for the results.

Performed the diluted CYA test. Results are 170ppm. Looks like I need to drain out at least 70% of water or around 13,000 gallons to get CYA down to 50ppm. The submersible pump I am using is rated at 1600 gallons per hour. So let pump run for about 8 hours?

 

[ATX61]

I don't know that "took 6 drops of reagent to lower to 7.2" means. Perhaps you're using the acid demand reagents? I never have, so can't advise on that. It doesn't matter for fill water. Your TA and CH are about as good as one can hope for for fill water. I don't see any special considerations there. Go ahead and exchange the water to bring the CYA down. Are you clear on the risks and your options for how to do that? And the instructions and steps? If not, ask away...

No I am not clear on the risks and options. This is my first go at this. Instructions and steps would be appreciated also. Not sure if I should do the exchange method or drain out what I estimate to be 70%-80% of water and refill. We do not have high ground water here if that is one of the risks. House is sitting on solid bedrock of limestone. Water here is sourced from an underground aquifer that is 300-600 feet underground. Yes I used the acid demand reagents although probably didn't need to. I agree the tap water results look good for fill water. I am starting to see some green algae form so looking to get it done this coming week.

 

[Dirk]

You can still add liquid chlorine at this point. Yes, you're exchanging, but don't let algae take over now, as you'll have to clean it up after the exchange.

Risk 1 you've covered. Risk 2 is the pool structure. The water is part of the structure. More so in a vinyl pool, but the water pressure can also acts on a plaster pool, too. Especially an older one. Sometimes it is that pressure that is keeping weak plaster from coming apart. Remove the pressure, and plaster problems can reveal themselves. It happened in my six-year-old pool! Plaster started blistering, and had to be replaced. This is very rare, and my situation was exacerbated by an acid wash gone bad. Pools are drained all the time with no issues at all. I can't advise on how you know ahead of time what you're going to get. I just know I'll never empty my pool again if I can avoid it, and would choose to do a no-drain exchange instead. That might be just me. More here:

Draining - Further Reading

www.troublefreepool.com

The submersible pump I am using is rated at 1600 gallons per hour. So let pump run for about 8 hours?

I'm not sure if that's going to work like that, because the rating is based on conditions you will not likely recreate (size of hose, height of hose over pump, how much water is in the pool (which will vary as you empty), etc). If you use a pump, I would place the pump in the pool, start the pump and capture the output in a five gallon bucket, and time that. Do that a handful of times to get a good average. Then calculate your gallons/hour from that. Then check that every hour or two to see if the rate is changing as the pool empties, or staying constant. Something like that.

I think someone else mentioned: overshoot what you think you need to drain. Better that than not enough.

 

[ATX61]

You can still add liquid chlorine at this point. Yes, you're exchanging, but don't let algae take over now, as you'll have to clean it up after the exchange.

Risk 1 you've covered. Risk 2 is the pool structure. The water is part of the structure. More so in a vinyl pool, but the water pressure can also acts on a plaster pool, too. Especially an older one. Sometimes it is that pressure that is keeping weak plaster from coming apart. Remove the pressure, and plaster problems can reveal themselves. It happened in my six-year-old pool! Plaster started blistering, and had to be replaced. This is very rare, and my situation was exacerbated by an acid wash gone bad. Pools are drained all the time with no issues at all. I can't advise on how you know ahead of time what you're going to get. I just know I'll never empty my pool again if I can avoid it, and would choose to do a no-drain exchange instead. That might be just me. More here:

Draining - Further Reading

www.troublefreepool.com

I'm not sure if that's going to work like that, because the rating is based on conditions you will not likely recreate (size of hose, height of hose over pump, how much water is in the pool (which will vary as you empty), etc). If you use a pump, I would place the pump in the pool, start the pump and capture the output in a five gallon bucket, and time that. Do that a handful of times to get a good average. Then calculate your gallons/hour from that. Then check that every hour or two to see if the rate is changing as the pool empties, or staying constant. Something like that.

I think someone else mentioned: overshoot what you think you need to drain. Better that than not enough.

Dirk, thanks for the input. It is an older pool, I estimate 20+ years old. It was re-plastered about 3 years ago. I am going to opt for the lower risk exchange method with pump placed in deep end and fill from shallow end. Checked fill water temp - 74. Pool is currently 72. I will calculate the pump output using 5 gallon bucket. Once I have the calculations for that I will run pump/fill water for what is estimated 70% -80% water exchange and retest for CYA.