Higher chlorine loss than last year

[dancu]

Found this site early last year, read and studied, got Ben's testkit and did BBB.
Loved it! 2 ppm loss per day without solar cover with a cya of 40 the whole summer.
This year it is 3-4 ppm, 2ppm with the cover!
I am starting to raise the cya and now it is at 50-60 but no improvement.
What could the reason be for the difference? Water is clear,no CC

Thanks

Dan

[dancu]

Help!!! now it is getting slimy in the corners!!!

[duraleigh]

Slime = algae

Use your test kit and bring your chlorine up to shock level and keep it there untill all signs of algae are gone.

Post a full set of test numbers from the kit and it may reveal a clue but I suspect your higher chlorine consumption is from the heretofore unseen algae developing in your pool.

[leejp]

Found this site early last year, read and studied, got Ben's testkit and did BBB.
Loved it! 2 ppm loss per day without solar cover with a cya of 40 the whole summer.
This year it is 3-4 ppm, 2ppm with the cover!
I am starting to raise the cya and now it is at 50-60 but no improvement.
What could the reason be for the difference? Water is clear,no CC

Thanks

Dan

Something's living in your pool... Bump it up to 15PPM and relax for a few days.

[chem geek]

Also, please let us know the minimum FC level when the CYA was at 40 and then now at 50-60. You referred to the FC loss, but not it's minimum level. It definitely sounds like the higher rate of consumption is due to fighting a nascent algae bloom and shocking (as recommended above) is the thing to do, but it would be good to know why this started in the first place and the minimum FC level might help us figure out if we need to adjust some recommendations.

[dancu]

test results 7pm

FC 6.5 (down from 9.5 at 7AM)
CC 0 ?
PH 7.4
ALK 120
CYA 65 (55 in sunlight)

Last night FC was 3.5 brought it up with 3 jugs of bleach (2.1ppm each)
to recommended cl levels for higher cya (60)
Before that I was running the pool at Cl for 30- 50 CYA
Tried never to let Cl fall below 3 but sometimes it went to 2.5,
after a party it was at 1 ppm once
What baffles me most is the CC being zero, I thought 0 CC means no algies, no shocking required.
Haven't been in the pool today so I don't know if the slime is gone with the CL up .
Do you guys still think I need to shock? (13.5ppm is 7 jugs! :-))
Thanks for your responses!

Dan

[duraleigh]

Do you guys still think I need to shock? (13.5ppm is 7 jugs! :-))
Thanks for your responses!Absolutely. Regardless of your tests, visible slime is algae. I would shock it tonight.

[dancu]

OK, will do, the slime is not visible though, it just feels that way...
Any thoughts on the CC being zero?

[chem geek]

If the pool has high levels of chlorine and/or exposure to sunlight, the CCs can stay near zero. It all depends on the nature of the organics in the pool. Some only slowly form CCs so sunlight can break it down as fast as it is produced. Others such as ammonia from chloramines very, very quickly and will register on the tests before they get broken down.

As recommended, I would shock the pool and also brush the sides. Though maybe you don't actually have algae, odds are you've got something that needs to be broken down and more likely than not it is algae trying to form. A slimy feel is probably an algal slime layer getting formed. Either that or your pool is oozing something :eek: it's alive, it's alive!

Richard

[dancu]

Brought it up to 20.5 ppm, pump is running
I will test and brush in the morning
Thank you again, you guys are great!

[dancu]

In the morning FC 20.5 8am s
Last night 9.5 7 pm
This morning 8.5 7am lost 1ppm overnight
Good enough or do I have to bring it back up to 20ppm ? ,slime is gone...

[chem geek]

Personally, I'd play it safe and keep it at shock level another 24 hours. A 1 ppm drop overnight is not huge going from 9.5, but it may indicate something is still getting killed or broken down even if it's not visible. Better safe than sorry.

[dancu]

Didn't play it safe and now I am sorry...3.5ppm at 5.30pm....
Back to shock level tonight...seems like an a large drop compared to overnight
even with the added uv.

[dancu]

6/24 pm 3.5 ppm, added bleach to 25ppm(9 jugs supposed to be 18.9 ppm,did I test to soon at 2 hrs?)
6/25 am 23.5ppm
6/25 pm 13ppm, added bleach to 25 ppm(4 jugs are supposed to be 8.4ppm but I tested a 12 ppm increase after 2hrs)
6/26 am 24 ppm
6/26 pm 12 ppm
6/27 am 11.5ppm
6/27 pm 5.5ppm
losing 6 ppm during the day, yes it was hot and sunny but I am in northern new jersey.....Any suggestions to bring this down?

[chem geek]

Other than using a cover, I'm not sure what to suggest. You are already at 60 ppm CYA. A 6 ppm loss out of 11.5 ppm is about half and given that you only lost 0.5 ppm at night it would appear that this loss is due to sunlight. This is the peak time of year and even in northern latitudes the amount of solar radiation is quite high. The difference in northern latitudes is that this situation doesn't last very long.

I used to think that operating at a lower CYA level would save you chlorine. So running at 30 ppm CYA you would go from 7 to 3.5 ppm FC and only use 3.5 per day which is less. But now we have reports and experiments (in this thread (http://www.troublefreepools.com/viewtopic.php?t=8&postdays=0&postorder=asc&start=20)) of CYA saving more chlorine even at the proportionately higher CYA levels. So that would say going to 80 ppm CYA or higher might help (the effect is non-linear) even maintaining the higher FC level. So I'm stumped and until we get a lot more data on true CYA protection of chlorine, I don't know what to say.

[dancu]

I am starting to think that a cya of 60 is a bad place to be because using Ben's
chart it puts me at the bottom value that requires 5 to 10 ppm cl
Could you help me out with the testing method?
Testing at 7pm with my back to the sun I test 60-65 cya
At 2pm back to the sun 55-60ppm, and if I face the sun I can squeeze out 45 -50 ppm.
Can I use lower scale of 3-6 ppm?
That would probably save me half....

[chem geek]

You are probably in the 60 ppm CYA range given what you described for testing. It's a hard test to get right and it has error of +/- 10 anyway. The minimum amount of Free Chlorine at that CYA level is 4.5 ppm (equivalent to the "Min" in Ben's chart) while a reasonable target (equivalent to a mid-point in Ben's chart) is 7 ppm. If you want to just make sure you never go below around 5 ppm, that would be OK, but this won't save you a lot.

It's really too bad it's not easier to change CYA levels since you could just try a lower level and a higher level to see if it made any difference (with corresponding lower and higher FC levels). You could take a large basin or bucket of pool water, dilute it with tap water to reduce CYA level and try that (adjusting FC level as needed). Then take your pool water in another basin (or the same one the next day) and add a little CYA to it and chlorine and see how the FC level holds up. It's not a perfect experiment because the depth of the basin or bucket isn't the same as your pool, but it's better than nothing.

Richard

[brent.roberts]

Question: when is the last time you cleaned out your filter.

Maybe there is a lot of junk in there that you can't see that is consuming some
of the chlorine.

Put a cover on to stop the sunlight loss. You're going to burn up the cost of a cover in extra chlorine. Even in NJ the sun is very high this time of year and the UV loss can be huge.

[dancu]

Oh, I like that idea!
Pool is 3 years old, sand filter never never got cleaned or replaced only backwashed
Drop in cl overnight while at shock levels with the filter running all night was minimal though...
Just thought about the light niches,what or the odds something is growing in there, or am I losing it now......

[brent.roberts]

If you got no significant drop in chlorine overnight, then I don't think gunk in the filter is the issue. From what I have seen in weather patterns most of NE USA and our area in Canada (Toronto) has had much greater than normal amounts of sunlight. We only got 1/4" of rain in June and normally get 2 1/2", so UV action on the chlorine will be much higher than normal. Maybe just carry on and see if it goes back to normal for you when we get more normal weather.

By the way, despite what some pool stores tell you, filter sand almost never needs replacing.

Good luck

[dancu]

Does high UV fluctuate daily or is it more seasonal?
I always thought it had a direct relation to cloud cover.
Today was cloudy, 9 ppm 6AM, 4 ppm 6 PM or do I need many cloudy days
for the effect of UV to drop?
Are there more factors related to UV strenght?

Dan

Buying stock in bleach factories

[chem geek]

Thicker clouds can block a lot of UV, but thin clouds may still pass 60-80 percent of the UV through (which is why you can still get sunburn even if you feel cool because thin clouds reflect most of the infrared heat). The UV is also directly related to the total radiation from the sun which changes by time of day and time of year, both relating to the angle of incidence of the sun relative to vertical. There is a direct angle effect (based on the cosine of the angle if vertical is 0 degrees) plus at lower angles there is an additional effect from the extra absorption by the sunlight passing through more of the atmosphere.

This link will let you see the amount of solar radiation in your part of the country at different times of year. HOWEVER, this is an average over day and night and includes the actual cloud cover. Even the "maximum" is for the month average, not a peak during the day with no clouds. You can see that the east coast and even Florida has lots of daily clouds that lower potential output compared to the southwest.

There was a link on the web to a calculator that would tell you the peak solar radiation at any time of year and time of day for a given latitude, but I can't seem to find that.

Richard

[dancu]

Just wanted to post some conclusions.
Never was able to lower the chlorine consumption this season.
Pool stayed cristal clear only if kept above 6 ppm, cya is 40 now
No chlorine loss overnight!
Loss per day is still 2ppm which is more than double compared with last year around this time.
I figure there is something else in the water that makes the cya ineffective.
Maybe antifreeze from last winter?
Any thoughts?
Also I am using Walmarts Ultra, which to me has a scent to it?

Thanks
Dan

[CarlD]

If you smell anything other than bleach, like a perfume, don't use it. Period.

One thing people forget is that each summer is different. One summer may be relatively bug (as in biters) free, the next may be mosquito-central. There's different levels of pollen, and other contaminants. It depends on the amounts of rain in the spring and summer and the amount of sunlight.

Saying that, this summer seems to have been one where there was a lot more biological stuff getting in the pools. My usual vacation ritual of having someone dump 1 gal of bleach in the pool every other day failed, and I came home to a mild algae infestation--for the first time. My system always worked in the past. So why did it fail? I don't know, but I just think there was more stuff to metabolize.

I don't know if this is right or wrong but it seems to fit the facts.