Where Has All The Chlorine Gone? Out by....

[NullQwerty]

Hey folks,

Going a little nuts here. All my chlorine is diminishing to almost 0 level over night. I'll put in two (or even four) of those big 2 gallon jugs of Ultra Bleach in the evening and raise it to between 5 and 10 ppm, and the next day, the chlorine is down to .25. I run the pump and/or the dolphin to mix the water too.

It's only been happening for a week now. At the beginning of the week, I had minor algae, but that's all gone and my pool looks fantastic. All other levels are right where they should be including CYA.

Could it just be Sun that's doing it? It's really not all that sunny though. What other factors are there? Could it be getting stuck in the bag of the dolphin?

Thanks

**Edit** It's not 2 gallons...it's 1 gallon 46 ounces. Sorry.

[donaldm823]

Hey folks,

Going a little nuts here. All my chlorine is diminishing to almost 0 level over night. I'll put in two (or even four) of those big 2 gallon jugs of Ultra Bleach in the evening and raise it to between 5 and 10 ppm, and the next day, the chlorine is down to .25. I run the pump and/or the dolphin to mix the water too.

It's only been happening for a week now. At the beginning of the week, I had minor algae, but that's all gone and my pool looks fantastic. All other levels are right where they should be including CYA.

Could it just be Sun that's doing it? It's really not all that sunny though. What other factors are there? Could it be getting stuck in the bag of the dolphin?

Thanks

I had the same problem last week, 2 days in a row chlorine went 0ppm with the water crystal clear. My fix was to shock the pool to 12ppm and run the pump/filter all night. Back press doubled overnight, meaning, something was in the the water that the shock took care of. I ended up shocking the pool a second time after the chlroine level got down to 5ppm due to CC being high after the shock. I surmise, you have something starting-need to get ahead of it by shocking

[mbar]

I second Don's opinion

[JohnT]

At the beginning of the week, I had minor algae, but that's all gone and my pool looks fantastic.

I suspect the algae isn't gone, but just being held in check by the chlorine. As the others said, shocking it will probably kill the algae and reduce your chlorine use.

[NullQwerty]

Welp, I shocked it last night. I'll report back in a day or two.

Thanks everyone!

[NullQwerty]

Well, I really shocked the pool the other night. 5 lbs of powder. Today I just went and tested it, and nothing. No chlorine at all. Some of the granules had sunk to the bottom, so I stirred that up. I then added another 3 of those gallons of bleach.

See what it's like tomorrow.

[aylad]

If you happen to have an old OTO test laying around, you might try using that for a quick test, just for grins.....I don't see how a pool that still is holding granules can test for zero TC. I think the testing is a bit suspect. I've never used the ColorQ, but something's not right. What is your CYA level?

Janet

[NullQwerty]

All 3-4 gallons of Bleach is gone. There is almost zero chlorine in there right now. It hasn't even been 24 hours.

I've been running the pump overtime too. About 16 hours a day.

Again, the pool looks great though.

The only thing I could think of is to shock it every night for 3 or 4 days in a row. Do you think I should do that?

Thanks!

[aylad]

If you have some organic load in the pool that is using that much chlorine, then shocking it only at night isn't going to win the battle--you need to shock it, and test 3-4 times daily and add more to get back up to shock level. It's maintaining that shock level that will kill off anything living in your pool. Letting the chlorine yo-yo up and down isn't going to accomplish anything if you're trying to kill some sort of bloom. That being said, I stick with my above post--I'm not so sure that your testing is giving you accurate results. What is your CYA level, and what are you using to test with?

Janet

[NullQwerty]

I had the same suspicion, so I had tested it with 4 different tests. Two different drop kits from HTH, 1 strip from HTH, and 1 strip from Leslie's pools.

All give the same results. I forgot the exact reading of the CYA, but I tested it multiple times and it was always at the perfect level.

Also, after adding 1 gallon of bleach and testing 3-4 hours later, the tests showed it at 2 ppm, so the test kits are working.

Thanks!