Noob, High CYA with TF-100 test kit

[JamesR]

Had always used Aquacheck test strips, bought the TF-100 kit to get a comparison. Both show high CYA levels. Is the only solution here draining part of the pool water and refill? I hope not, because that is a hack of a lot of water!
TF-100 kit shows:
FC = 2 ppm
CC = 0 ppm
CH = 250
TA = 70
CYA = 80

My dip and read test strips show:
FC = 3
CC = .5
CH = 250-ish
TA = 80-ish
CYA= somewhere around 100

Yes, there has always been a Hayward inline chlorinator hooked up. Aren't there any tabs to put in there that do not raise CYA over time? Adding bleach daily seems to be impractical. What do you folks do for pool chlorine levels if you go away on a week long vacation? I kind of look at the upcoming weather and either dial up or dial down the chlorinator. I was gone for the past 8 days, came home today and the above readings are where it is at. Before I left, everything was identical except I had 5ppm FC

TIA,
Jim

 

[jblizzle]

Yes replacing water is the only option to lower the CYA ... although if you are at 80ppm, that is not too terribly high.
No there are not any tabs without CYA.

You can get feeders to automatically add liquid chlorine (Stenner pump) or many members go to a SWG system.
If your CYA were not too high, then you could use the tablets when you are on vacation.

Your FC is much too low right now and that lets algae start. See the FC/CYA Chart.

 

[JamesR]

........Your FC is much too low right now and that lets algae start. See the FC/CYA Chart.

Yes, I see that. I just picked up a couple of gallons of generic bleach at the grocery store. Labeled as extra concentrate 8.25%. Not bad at $2.49 each. So I am going to start with 1 gallon of that and then maybe slowly over the next few days do some draining and garden hose re-filling purely to get an handle on the CYA.

 

[Texas Splash]

Jim, I was at 90 CYA last year before I learned TFP. With all the TX rain and turnover of water in my pool, I actually had to add stabilizer for this first time this year because I was below 30. Just stick with the liquid chlorine for now to avoid raising CYA any further. As already mentioned, the tablets are an option when you're out of town for an extended period of time, but you just need to have a good handle on the CYA first. Once your CYA comes-down, adding a little bleach each morning or evening is not too much of an inconvenience when you have crystal clear water. Oh, and now that you have the TF-100, don't bother with the test strips or going anywhere else for advice. YOU are in charge now with one of the best kits available. Trust your own readings, but if you have a question about your TF-100 tests, feel free to ask.

- - - Updated - - -

$2.49 is a great price per gallon.

 

[jblizzle]

Why 1 gallon of bleach? Is that based on a calculation or a guess?

Are you using PoolMath?

 

[bdex]

If you get off of the tabs like Texas said above you will slowly over time lower your cya with partial drain/splash out and refills. A couple extra long backwashes and some good cannonballs and it will come down over time.

I have read of a chemical that claims to remove cya from the water. I do not know of anyone that has used it yet.

I have a swg pool so vacations are no problem. But as jbizzle said, Stenner pump with bleach works as well. I would keep your chlorinator hooked up because if you have a low enough cya you could throw a few tabs in there for a vacation or two.


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[JamesR]

Why 1 gallon of bleach? Is that based on a calculation or a guess?

Are you using PoolMath?

I used the pool math calculator online. Based on my CYA, I wanted to be at a minimum of 5ppm FC and a target of 8ppm. It had me adding 166 oz of bleach based on the "advertised" 8.25% concentration. I almost never add the full does of anything right off of the bat, so I went with 128 oz for now to see where it gets me. 2 hours later, I have an FC of 7ppm now, 0 CC. So I believe I am good for now as far as chlorine levels based on the slightly high CYA level.
As the others have advised, I have turned off the auto tablet chlorination and will let time and usage drop the CYA for now while adding liquid bleach to keep things in check. Draining 10,000+ gallons from my pool would be a PITA right now.
Sound good??.

 

[jblizzle]

Sounds good

The most important thing is to keep the FC above the minimum at all times ... so you may want to target a little higher.
If your volume is set right, PoolMath is very accurate and you can add all that it recommends.

 

[JamesR]

Sounds good

The most important thing is to keep the FC above the minimum at all times ... so you may want to target a little higher.
If your volume is set right, PoolMath is very accurate and you can add all that it recommends.

Yea,... my volume is real hard to figure out. I am going by what the blueprints said for when the pool was built. (Approx 28K gallons), So I usually sneak up on the chemicals instead of dumping the entire does at once. Easier to add more than try to get it back out. As far as keeping the FC at the target, what is the level where it would be too high to swim in? For example, if someone had very high CYA and therefore had to keep the FC at 9ppm just to be sanitized and avoid algae, would that be considered too high for swimming in? Done asking questions for now.... just replaced the light fixture in the deep end and am going to go out now and enjoy the pool.

 

[Richard320]

Yea,... my volume is real hard to figure out. I am going by what the blueprints said for when the pool was built. (Approx 28K gallons), So I usually sneak up on the chemicals instead of dumping the entire does at once. Easier to add more than try to get it back out.

Smart man.

As far as keeping the FC at the target, what is the level where it would be too high to swim in? For example, if someone had very high CYA and therefore had to keep the FC at 9ppm just to be sanitized and avoid algae, would that be considered too high for swimming in? Done asking questions for now.... just replaced the light fixture in the deep end and am going to go out now and enjoy the pool.

Shock level with 80 CYA is roughly 32. You're way below that, so it's safe to swim. I started with CYA around 240 and water restrictions in place. We swam in 20 FC with no ill effects. The CYA buffers the bleaching action.

 

[JamesR]

Smart man.

.....I started with CYA around 240 and water restrictions in place. We swam in 20 FC with no ill effects. The CYA buffers the bleaching action.

Wow,...I would have thought the entire family would have had bleach blond hair after that swim!
Good to know.

 

[pooldv]

Another option when heading out of town is to bring the chlorine up to shock level right before you leave. We have SWG, but I always add some extra bleach when I am not going to be able to test and keep an eye on it for a bit.