Bleach not staying in pool?

I've read previous posts on this matter, here is my available info :
CL level (hovering between 1-2ppm)
PH 7.4
Alk 110
Cya (was around 60/70 last time I checked ..out of test fluid)
20k IG gallon pool w/ electric cover

so I'm not losing CL from the sun because I'm covered most every day 'cept swim days ...

I had a possible algae bloom 3 weeks ago , brought CL level up to 7-10PPM , also threw in yellow out (20k gallons, 2 bags) cleared the pool within a week...

could I be getting a false reading due to something? If the pool is clear & free of Algae , what could be consuming 10% liquid bleach (1-2 gallons) over night

thanks!
KE

KE,

Can you do a Combined Chloramines test (CC)? If not, I suspect you are still losing it to organics still in the pool.

To the best of my knowledge, sunlight and organics are about the only two things that make it go away......for example, the few indoor pools you see on here usually have the problem of too much Cl and no way to get rid of it...it's just too clean.

I have no idea what's in yellow out or it's function but it sounds like to me you simply need to bring your Cl levels up til they stabilize....perhaps to shock level.

Can you smell Chlorine when you walk around the pool? That's an indicator you need more Cl. :)

I suspect that maybe you didn't kill all the algae. With a cya of 60-70, the chlorine level you need to regularly maintain is 5-10. You said that you raised your chlorine level up to 7 to try and kill the algae. That isn't high enough for your pool. Shock level for a pool with that much cya is about 20ppm. Take a look at the chart at the following link. I have a feeling that may be the problem - that you really didn't eradicate the organic stuff in your water. Like Dave said, you will probably find that you have a CC reading. My advice is to shock the pool for a few days. Try and maintain the high level without letting it yo-yo up and down. To do this, you'll need to test at least a couple of times a day (3x a day is even better) and each time add enough bleach to take it back up to shock level. BTW - uncover your pool while your chlorine level is high so you won't damage your cover.

http://www.poolforum.com/pf2/showthread.php?t=365

Check out this page on Poolsolutions. Ben talks about how 'chlorine enhancers and boosters' contain either ammonia or bromine and will cause a HUGE chlorine demand after you use them. Yellow Out is one of the products he mentions.
http://www.poolsolutions.com/tips/tip44.html

He also says on the page to send him a message if you have used one and your Cl has gone AWOL!:eek:

Evan,

That is an excellent post. You do great research and that's a potential solution that not many would've recognized.

Okay, I'm done being Mr. Nice....back to my cynical self!! :D

H20man, my bet is Waterbear has posted your answer.....I would still test for CC's but keep adding Cl in there and see if it doesn't stabilize soon.

thanks 4 the help!

I suspected the Yellow Out was the culprit, but I figured after 3 weeks it had run it's course & be back to normal.....

also , can u have algae hanging on even though pool is clear?

I hate to leave the pool cover open because I lose degrees! :( but don't wanna fry it too!

thanks again

GASP! I think I am going to faint! I got a compliment from Dave!;)
(just kidding, I thank you for the compliment! I HAVE studied the Poolsolutions sight to try and learn everything I can on there and just reread it again about a week ago so it was fresh in my mind :))

Seriously h20man, If the product was ammonia based it will create a HUGE chlorine demand and if it is bromine based then you might have a bromine pool for a while. If it is bromine then check out this page on Poolsolutions
http://www.poolsolutions.com/tips/tip10.html

I tried to find a MSDS for Yellow Out but they don't have one on the website. Are the ingredients listed on the package? That would be helpful.

Just 'from the hip', I'm thinking the 'yellow out' had bromine as it's key ingredient. (I'll try to remember to check the store room at work tomorow) If that is the case, then the low reading is caused by your checking a bromine pool for chlorine - see Evan's link to Ben's take on "once a bromine..." topic.

Re-reading Ben's article that Evan linked to makes me doubt that the single dose of Yellow Out is the culprit, especially if bromine is the primary ingredient. Ben refers to "repeated or excessive doses" which a single, normal dose of yellow out wouldn't seem to be. Also, when testing with DPD, doesn't bromine show up just as chlorine would? In other words, wouldn't every ppm of bromide ion that was converted by the chlorine into free bromide, thus "consuming" the free chlorine, show up on on a DPD test just like free chlorine?


Just a thought.

Not really because the bromine reading is 2.something of the chlorine reading (I think it's 2.25 but don't hold me to that!) so if he was showing 1 to 2 ppm chlorine in the pool and was actually testing bromine it would have been over 2ppm to over 4 ppm bromine level.