Yes, another high CYA question...

[55gibber]

Hi folks, I'm very new to this forum but so grateful that you all are here, sharing your expertise and experience. We've been in our house just a little over a year - first time with a pool. About 5 weeks into our second pool season. Last year, I relied heavily on our pool store. When we opened the pool it had been covered for two seasons so it was all green... cleared up within about 7-10 days though. All season long we had high CYA levels (>200) but the pool looked great. Pool guys basically said not to worry about the CYA. Used chlorine pucks and really that was about it once it got balanced at the start of the season. Midway through July, we installed an automatic pool cover, so it's covered most of the time unless we're actually using it.

This year, based largely on information gleaned from this forum, I've decided to abandon the pool store and do things myself (though they did open it for me). Lots of learning to do. I've been reading as many articles as I can find about CYA, the issues with high levels, and the relationship between CYA and Cl. Here's my dilemma. The pool looks great. No algae. No unpleasant smells. I'm in the medical profession, where we're taught to 'treat the patient, not the lab test'. I hate the idea of replacing 75% (or more) of the water in my pool based purely on a number and I naturally lean towards the 'if it ain't broke...' philosophy.

1. Is it possibly that the water is clear but still harboring problems and is there any way of testing for those problems?
2. What are the downsides of running my Cl levels very high, and replacing water gradually over time with bigger than normal backwashes?
3. Do I just need to suck it up and do a refill?

Yesterday at 630am, Taylor K-2006.

FC - 5
CC - 0.5 (I guess really it's somewhere between 0 and 0.5 given my sample size)
pH- 7.6
TA - 130
CH - 100
CYA (dilution method) - 180? 140? I first thought 180 then realized I could still see the black dot though it was quite faint. Couldn't see it at all at 140.

Thanks!!

 

[YippeeSkippy]

Hey there 55Gibber How easy would it be for you to drain and refill the pool, perhaps half way but twice? That would certainly help your CYA situation immensely.

The potential downside is that *if* an algae outbreak occurs, the cure will be more painful than if your CYA was at a more manageable level.

Have you ditched the pucks and gone to liquid chlorine yet?

Maddie

 

[jobybett]

Hi 55gibber,

I'm very new to all this myself, so stick with what the experts suggest, but I have the same problem as you, swapping from a pool store run pool with >200 CYA to doing it myself.

From what I have read/researched in the last week, the only other method to reduce the CYA is to get a RO (reverse osmosis) company to come and "clean" your water, that's if there on available... I was quoted $600 for a 22k gal pool

Needless to say, I'm going for the 50% drain option, but I really think doing it will make for a much easier time managing the FC.

Good Luck!

Joby

 

[laprjns]

When I started with the TFP method back in 2013, I was in a similar situation with cya in the 120 to 140 ppm range and I wasn't crazy about the idea of draining 1/2 to 3/4 of my pool water. So I lower it by slowly bring my cya down over the season. I managed it by ensuring that I always had the appropriate FC levels for my cya. I got the cya down to around 60 ppm by the end of the season by back washing, drawing down water level before rains, even watering my lawn with the pool water. Looking back at my logs I was maintaining FC levels of 10 to 14 ppm during the early part of the season and bought it down as my cya level came down. Once the FC level has been achieve, maintaining it is just replacing the daily loses. The risk is of course is that if you do get algae then its going to take more chlorine to SLAM and clear your pool. This risk can be mitigated by using an automatic chlorinator like a Saltwater Chlorine Generator, Stenner Pump, or Liquidator. I used a Liquidator and never ran into an algae issue,

 

[Richard320]

1. Is it possibly that the water is clear but still harboring problems and is there any way of testing for those problems?
2. What are the downsides of running my Cl levels very high, and replacing water gradually over time with bigger than normal backwashes?
3. Do I just need to suck it up and do a refill?

You can check to see if anything is growing in the water by running Overnight Chlorine Loss Test

I took control of my pool after the previous homeowner and his pool service ran my CYA up to 240ish... and severe water restrictions ruled out a drain and fill. Running a pool with high CYA can be done, I've done it. I also don't recommend it. For starters, you need to maintain really high FC. Which means every single FC test has to be done with the FAS-DPD test. The extra reagents probably cost as much as the water, once refilling was allowed. Second, the pH test is always suspect with FC so high. It took me a couple years of replacing a few inches at a time and capturing all the rainwater I could (not much--drought years) to dilute it. Third, if algae ever does get a toehold, the shock FC level will be higher than any tester can read and you'll have to drain then and the whole while you're waiting for it to fill, the algae in the residual will be growing.

It is much much easier to maintain at a reasonable CYA level.

You have a vinyl liner, so you never want to empty it completely. Do one drain and leave a foot or so in the shallow end and then refill. Let it mix, and see what you end up with. Enjoy the pool a few days, and drain some more. I use mine on the lawn.

 

[Autonoz]

Just a question that pertains to this topic. My CYA is in the upper 100's. I use tablets as that is what my pool guy uses. I am going to start taking care of this myself. I was advised not to drain the water in the heat of the Arizona summer. Is this true and what is the reason?

 

[55gibber]

Looks like it would cost me about $1000 to refill half the pool.

Yes - pucks and I have definitely parted ways!

Hey there 55Gibber How easy would it be for you to drain and refill the pool, perhaps half way but twice? That would certainly help your CYA situation immensely.

The potential downside is that *if* an algae outbreak occurs, the cure will be more painful than if your CYA was at a more manageable level.

Have you ditched the pucks and gone to liquid chlorine yet?

Maddie

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- - - Updated - - -

Interesting... I wonder if that's an option here. A 50% refill will cost me about $1000 plus the cost of chemicals

Hi 55gibber,

I'm very new to all this myself, so stick with what the experts suggest, but I have the same problem as you, swapping from a pool store run pool with >200 CYA to doing it myself.

From what I have read/researched in the last week, the only other method to reduce the CYA is to get a RO (reverse osmosis) company to come and "clean" your water, that's if there on available... I was quoted $600 for a 22k gal pool

Needless to say, I'm going for the 50% drain option, but I really think doing it will make for a much easier time managing the FC.

Good Luck!

Joby

- - - Updated - - -

Interesting - thanks for sharing your experience. I'll have to look into those automatic chlorinator options. I've been adding liquid bleach over the past few days... as of this AM my FC is 10.5-11. After reading more posts, I found some good suggestions for how to most accurately do the CYA test... I'm going to try to do that today and see if I can get a more accurate measure.

When I started with the TFP method back in 2013, I was in a similar situation with cya in the 120 to 140 ppm range and I wasn't crazy about the idea of draining 1/2 to 3/4 of my pool water. So I lower it by slowly bring my cya down over the season. I managed it by ensuring that I always had the appropriate FC levels for my cya. I got the cya down to around 60 ppm by the end of the season by back washing, drawing down water level before rains, even watering my lawn with the pool water. Looking back at my logs I was maintaining FC levels of 10 to 14 ppm during the early part of the season and bought it down as my cya level came down. Once the FC level has been achieve, maintaining it is just replacing the daily loses. The risk is of course is that if you do get algae then its going to take more chlorine to SLAM and clear your pool. This risk can be mitigated by using an automatic chlorinator like a Saltwater Chlorine Generator, Stenner Pump, or Liquidator. I used a Liquidator and never ran into an algae issue,

 

[Richard320]

Doublecheck that cost estimate.

30000 gallons is 4000 cubic feet. I'd call the water company and see about getting a waiver on the sewer charge for filling the pool. You could refill the whole thing for under $250 if they'll do that. City of Charlottesville : Rates & Fees for Gas & Water

 

[55gibber]

Thank you for the info. I will definitely give this some serious thought. I talked to a water delivery guy yesterday who seems good and comes recommended. Each 4000 gallon delivery costs $260, so doing half my pool will be 4 deliveries and about $1000. Since he can only do 4k at a time, it would give me some time to monitor the changes and see how things are going.

My pH read at 7.8 this AM up from 7.2 a few days ago - not sure if this is due to the issue you mention below or if the result is real - not sure what would cause that rise. All I've done in the last few days is add a few gallons of liquid bleach.

-Jason

You can check to see if anything is growing in the water by running Overnight Chlorine Loss Test

I took control of my pool after the previous homeowner and his pool service ran my CYA up to 240ish... and severe water restrictions ruled out a drain and fill. Running a pool with high CYA can be done, I've done it. I also don't recommend it. For starters, you need to maintain really high FC. Which means every single FC test has to be done with the FAS-DPD test. The extra reagents probably cost as much as the water, once refilling was allowed. Second, the pH test is always suspect with FC so high. It took me a couple years of replacing a few inches at a time and capturing all the rainwater I could (not much--drought years) to dilute it. Third, if algae ever does get a toehold, the shock FC level will be higher than any tester can read and you'll have to drain then and the whole while you're waiting for it to fill, the algae in the residual will be growing.

It is much much easier to maintain at a reasonable CYA level.

You have a vinyl liner, so you never want to empty it completely. Do one drain and leave a foot or so in the shallow end and then refill. Let it mix, and see what you end up with. Enjoy the pool a few days, and drain some more. I use mine on the lawn.

- - - Updated - - -

Unfortunately I'm in the county and on a private well...... Just doing a minimal refill resulted in decreased water pressure that started to make me nervous about continuing to use the well for the pool....

Doublecheck that cost estimate.

30000 gallons is 4000 cubic feet. I'd call the water company and see about getting a waiver on the sewer charge for filling the pool. You could refill the whole thing for under $250 if they'll do that. City of Charlottesville : Rates & Fees for Gas & Water