Hot climates chime in.. how much CYA do you lose?

[djdonte]

Between evaporation, rain and a very small leak I have on my return plumbing I am losing CYA. I have to bump it up by running trichlor tabs maybe every 2-3 weeks. I have to fill the pool a little maybe once a week. Part of this is due to my two skimmers not being even as far as elevation. I've had this leak all year, but haven't had CYA problems until it got real hot.

How much CYA do you guys lose in the summer? I like to keep mine at 50 or else I lose too much FC during the day. I test FC a few times a week, and my pool uses 1/2 gallon of 10 percent a day. When I start using needing more, I check CYA and lo and behold its 30-40.

This isn't a huge deal since I have a ton of tabs leftover from my pool store days, but I want to save some for vacations. Eventually I will have to buy powder CYA I suppose. I was hoping to just live with the leak and not have to cut into anything before I go salt next year.

 

[Psycho1122]

This summer (my 1st.) I have observed a CYA loss of 10 for the months of June and July. The sweet spot for my pool is 40-50. I will loose about 3 ppm CL per day and I keep the level at 7ppm. I add every evening after sundown and i rarely see a 1 ppm drop over night. My average CL use per day for the month of July was 48 oz. August so far has shown a significant drop in CL as the direct sun is diminishing.

 

[djdonte]

I wish I could say the same about the sun... still triple digits here. What do you use to add CYA?

 

[Psycho1122]

Oh yes, we are still in the triple digits here also. We will flirt with 110 by next Friday. Just dryer overall. If I need a CYA "bump", I will add pucks to the Deck Chlor.

 

[Arizonarob]

Just to give you an example. I bump my CYA up to 70 in April, then by September I’ll be right around 40. It’ll continue to drop to 30 by November, where I keep it till the following April.

 

[mknauss]

FYI - Evaporation has no effect on CYA levels.

I lose about 15% of CYA each month in June, July, and August. Primarily tied to warm pool water temperatures (near 90F).

 

[djdonte]

Just to give you an example. I bump my CYA up to 70 in April, then by September I’ll be right around 40. It’ll continue to drop to 30 by November, where I keep it till the following April.

You are salt I'm guessing?

FYI - Evaporation has no effect on CYA levels.

I lose about 15% of CYA each month in June, July, and August. Primarily tied to warm pool water temperatures (near 90F).

How do you replace? With pucks or CYA in a sock? I've heard it doesn't dissolve well.

 

[Arizonarob]

You are salt I'm guessing?

No. With the sun as strong as it is, it helps keep my FC from rapid burn off. If I was running a SWG, I would run my CYA at 90.

 

[djdonte]

Oh wow you must get a ton of sunlight. My pool is right up against my home on one side and trees the other, so I really only get direct sunlight a few hours a day.

 

[Arizonarob]

I get full sun (I even have a shade sail on half the pool) from 8 to 4 daily. The swing in FC usage between summer and winter is huge. 1 quart a day during summer, to 1/4 cup a day during fall/winter.

 

[jtpipkin]

would love to share that info with you, but that would assume any of us actually know what our CYA is - doesn't matter which test I use or how many times I do it, I swear I get a different result

 

[djdonte]

Marty showed me a really good way: Mix your solution and instead of watching the vial as you fill, fill it in increments. For example, fill it to 80 then hold it down by your waist and GLANCE at it in sunlight. If you see it with a quick glance, fill it 70 and do it again. Once you get to the level where you no longer see the black dot with a quick glance you are done. If it stops in between a number, round up. I tried that bulldog test too and it uses too much reagent. I use marty's method with the small vial.

 

[jtpipkin]

Marty showed me a really good way: Mix your solution and instead of watching the vial as you fill, fill it in increments. For example, fill it to 80 then hold it down by your waist and GLANCE at it in sunlight. If you see it with a quick glance, fill it 70 and do it again. Once you get to the level where you no longer see the black dot with a quick glance you are done. If it stops in between a number, round up. I tried that bulldog test too and it uses too much reagent. I use marty's method with the small vial.

When I use my taylor test, I follow his advice. But even bought a Blue Devil tester and ran it last night. Got 60 3 times and then went back a minute later and got 70... Maybe it was the time that made the difference, but that test tests my patience more than my CYA... everytime. Dang that little black dot?

 

[djdonte]

Ahh I meant blue devil not bulldog lol. It is very subjective and takes practice. I think consistency is key as far as lighting conditions. I get a different reading if I do it outdoors vs indoors.

 

[manfacro]

In the summer here, I loose about 10-20 ppm a month in CYA. However I do loose salt and calcium hardness steadily due to having to drain the pool after a rainstorm.

I have to bump all three up regularly.

 

[Salt_Water_Sam]

This is an extremely dumb question but how does CYA leave the pool other than splash out or backwash? (or maybe this is a dumb question that requires a very technical answer -- eager to learn)

 

[mknauss]

At higher pool water temperatures CYA does naturally decline at low rate. There is also a bacteria that will consume CYA but that occurs over winter with high organic loads in the water.

 

[djdonte]

Makes sense... jumped in my pool this evening and it felt like a warm bath.

 

[Wobblerlorri]

The thing about the Blue Devil or Pentair tests (I use the Pentair test, just like the BD test) is that you have to wait 2 min for the cloudiness to develop, then read it within 3 min, for a total of 5 min developing time. After that you get invalid results. That's straight from the Pentair instructions.

I had 40 ppm CYA in June, and thanks to sun, rain overflow, splash out and backwash/rinse, I've lost 10 ppm, down to 30 ppm. What's odd is PoolMath says to add 5.4 oz to raise CYA 10 ppm -- it actually takes 12 oz for mine to raise 10 ppm. Bad powder? Bought it at HD in May.

 

[djdonte]

I don’t really trust chemicals from HD besides the chlorine. Check the Julian date to see how long it’s been sitting there in the sun. CYA seems reasonably priced on amazon.