CYA levels in the sun

[dombey]

Hi,

Well I just anniversaried my pool ownership and I'm happy to report that TFP has helped me through an entire year without any adverse events (blooms, etc). Thanks guys.

The one thing I'm hoping to improve upon this year is my chlorine consumption. I have (as you can see below) a 28,000 gallon pool in sunny Phoenix AZ. What the signature does not say is that the pool is in direct sunlight ALL day, and we have no trees close enough to even provide a little bit of shade. As a result, I burn through a LOT of chlorine (at least it SEEMS like a lot).

After discovering something like 300+ CYA when I moved into the house, I drained all of the CYA out and replaced it with water.
I went with ~50 ppm of CYA and gave it a season to see where my consumption was at. On average, I went through 1/2 gallon of 10% every day, which adds up to something like $50-60 a month in chlorine expense.
Obviously the solution is to buy a SWG when I redo the pool, but that is a few years off since we have a major backyard overhaul scheduled where we'll do the patio, yard, pool, pool equipment all at once.
So...in the meantime I want to maintain my beautiful pool balance but also don't want to be dumping 1/2 a gallon a day in there... I've seen some people in PHX or similar areas go with 60-70...wondering if that will make any substantial difference, or do I need to kick it up a few notches? What is the highest you can go without sacrificing the effectiveness of the chlorine?

 

[woodyp]

I feel your pain. Texas pool in full sun all day and it uses a gallon of 6% per day when it warms up. I try to keep CYA at 50---------and may experiment with higher levels this summer. I bump FC to 8 and lose on average 3.5 4 ppm per day.
I think we're just victims of our circumstances though.

 

[JasonLion]

When you have really large amounts of direct sunlight on the pool it is often worth bringing CYA up to 60 or 70.

However, before you add any more CYA you should do an overnight FC loss test, just to make sure you don't have a low level algae problem. Sometimes there can be just enough algae to use up extra chlorine, but not enough to be visually obvious.

 

[dombey]

When you have really large amounts of direct sunlight on the pool it is often worth bringing CYA up to 60 or 70.

However, before you add any more CYA you should do an overnight FC loss test, just to make sure you don't have a low level algae problem. Sometimes there can be just enough algae to use up extra chlorine, but not enough to be visually obvious.

I will definitely do that. One of the things I added to my chemical arsenal this year is a FAS DPD kit; which should arrive this week....that will give me a lot more capability than I had last season.

 

[kal2002]

I went with ~50 ppm of CYA and gave it a season to see where my consumption was at. On average, I went through 1/2 gallon of 10% every day, which adds up to something like $50-60 a month in chlorine expense.
?

Hi dombey. Thank you for asking the quesiton. I can totally relate to your experience. The monthly expense is one thing (we were paying more than that for the monthly pool service prior to discovering this forum) but it is the chore of adding the chlorine daily and hauling it home by the ton every month that was getting old. So I think I will let CYA increase to about 60 this summer and see how it works. I will continue to test for FC daily in the summer but instead of using only 10% chlorine, I plan on using some trichlor tablets to increase CYA level slowly.

 

[dombey]

Hi guys,
as an update, I shocked my pool with some dichlor to a) ensure I don't have a low-level algae problem, and b) raise cya levels.

I let my FC drop back down to normal levels, and now my overnight FC test w/ my FAS DPD kit shows no noticeable loss overnight.

Oddly enough, I did a CYA test this morning and it appears to be in the 70-ish range even though it should be around 60 based on my poolcalculator inputs...but I think the CYA test is somewhat spotty for more reasons than one.

Right now I'm losing ~1ppm per day over the last 5 days, but it was cloudy a few days and the water is still pretty cold. It's supposed to be 98 degrees today and as the pool warms up and the sun stays overhear longer, I'll report back how this compares to last year.