My P.O.P. is gone. need help again

[PoolDoc]

http://www.swimpool.com/category_Swi...Pool_Algae.htm
http://www.swimpool.com/category_Poo...Chemicals_.htm

If you are sure that you have high CYA, and are sure you haven't used any United Chemical products (or other products containing bromide or bromine), we are in uncharted territory. The only thing left to do is a full blown test comparing your pool water with both stabilized and unstabilized tap water. You'll need 3 identical clean buckets that hold at least 3 gallons (and you'll have to clean them again), some liquid stabilizer, some bleach, a set of plastic measuring spoons down to 1/8 teaspoon, and a clean 1 gallon milk jug.

Lemme know when you have those items.

Given the circumstances, it's the only way to establish that you have some unknown 'bad actor' in your pool. If we do establish that, you'll then have to hire a pool service guy to help you drain and refill it safely.

In theory, you could send your pool water off to a water analysis lab, but we don't know what you are looking for, and the sort of analysis that would help in these circumstances would start at over $1,000 and go up from there.

Ben

[shub_31]

Im going away for a week this sat. My neighbor is going to put a 3qt bottle of 12% in each day. So whatever it is it is. Ill be curious to see it when I get back without the testing.
Also, I swam last night til 8 tested water and covered it
FC 12
CC .5-1

This mourning
FC 11
FC .5

Left covered all day with minimal sun. No pump run through night and day. First time in 3 months

4:30
FC 10
FC .5

Dont think I have any major problem.Maybe its just normal with the dog, lotions and sun to lose like I have been.
Ill let you know what I decide about the tests you want to run. Im also going to have a pool store test my water for kicks. Thanks for eveything

Scott

[PoolDoc]

Left covered all day with minimal sun. No pump run through night and day. First time in 3 months
4:30
FC 10
FC .5

You don't have any sort of cartridge or ozonator or extra filter or other gizmo installed, do you?

I'll let you know what I decide about the tests you want to run.

Uh, you might have not meant that exactly, but we don't have any particular desire to run them. It's just that -- unless there's something you've overlooked or forgotten to tell us -- there's nothing else we can do to explain your situation.

As far as we know, chlorine in an unused swimming pool with CYA=100 does not drop like that, unless bromine / bromide or iodine is in the pool.

[shub_31]

no nothing extra. You told me to let you know when i get the things needed. I just meant that I let you know if I decide to waste your time running them.
You mean to tell me that a coverd pool with minimal sun, pump not running isnt gonna loseat least 1ppm in 11hours.

[PoolDoc]

Not what I'm saying.

Your losses the previous day were what I spoke of. The losses you are reporting now aren't consistent with those, either.

[shub_31]

Sorry. I just thought that it might be normal for my pool and conditions to lose what it does after seeing that it didnt lose much with no one in it and less sun.

[PoolDoc]

It's not normal for a *stabilized* chlorine pool. It *is* normal for an unstabilized chlorine pool. And, it *is* normal for a bromine pool.

But, odds are, it will resolve itself over time. Even bromine -- unless you used the bromine tabs, which contain hydantoin -- will eventually be converted to bromate.

[chem geek]

If there is no sunlight and no bather load and an FC that is roughly 10% of the CYA level, then 24-hour chlorine loss is typically under 1 ppm and sometimes under 0.5 ppm, but the exact loss depends on temperature. In my own pool at 88ºF that number is on the order of 0.7 ppm FC per day (with normal bather load and the pool cover open 1-2 hours most days and longer on weekends and 40 ppm CYA, the loss is closer to 1 ppm FC per day). For residential pools that usually have a low bather load but that don't have a pool cover and are exposed to sunlight, the usual daily chlorine loss is around 1.5 to 2.5 ppm for most pools though some may be higher if there is heavier organic load such as blown in pollen, etc. This loss rate is also a function of the CYA level where higher CYA levels (with proportionately higher FC levels) lose less chlorine.

[shub_31]

all I can say is my cya is 100 and starting of with a FC of 10. Introducing a kid or kids with suntan oil and a dog and sun my pool will be down to 5ppm in several hours. Ive bought so many jugs of bleach im losing track of the money im spending. O well ill see what happens the rest of summer and hope next year is betterm thanks for th great replies

Scott

[chem geek]

A dog is equivalent to many bathers and if the kids urinate in the pool then that can also create a large demand, but it sounds like this happens every day for you, not just for such one-time incidents. Are you saying that if kids and dog do not get into the pool and there is just sunlight that the FC doesn't drop or are you saying that it does? I'm trying to understand if it's specifically the introduction of the kids and dog that are causing the drop.