High Daily Chlorine Demand

[indycreed]

I switched to BBB about a month ago. I've gone through two shocks (about two weeks apart) that lasted a good four days each. Currently my overnight chlorine loss is <1.0ppm and CC<.5. My CYA is around 60.

My daily chlorine consumption is running a pretty steady 8ppm per day. I can't figure out why it is so high. The water is getting a very salty taste and I'm concerned about corrosion of my pool equipment.

I live in Indiana and my pool gets about 12 hours of sunlight. I need some help on what to do. The amount of bleach I am pouring in at night is getting ridiculous.

 

[Richard320]

Please don't be insulted, but from where are you getting your readings? Taylor kit, test strips, pool store? You either have an algae bloom you're just barely keeping in check or the CYA is not what you think it is.

 

[frustratedpoolmom]

What is your target for dosing? What time of day are you adding the chlorine? Are you testing 1 hour after to confirm you have in fact, reached your target? What brand of bleach?

What are you testing with?

 

[indycreed]

I use the Taylor k-2006. I add (wal-mart) bleach in the evening - I know I'm supposed to target around 7, but I've had to raise it higher in anticipation of the loss. I generally do re-check to make sure I hit target, but not always. I've re-checked my cya lately, so I feel pretty confident that it is around 60.

If I have to go through the shock process again, would it be better to use burn-out instead of bleach? I know it's more expensive, but I'm already spending enough as it is.

 

[indycreed]

Okay - I still need help here. I did another overnight test and lost 2ppm. Now what? Obviously I'm fighting something that doesn't want to go away. My worries about another shock are
1. Damage to my vinyl liner?
2. Damage to my pump/filter?
3. Increase in salt taste.

Help please!

 

[Brentr]

I am thinking that you need to post a full set of numbers so that the moderators can help you. Just my thought.

 

[indycreed]

FC=5.5
CC<=.5
ph=7.7
TA=150
CH=150
CYA=60

 

[frustratedpoolmom]

Go to the pool store and ask them to test your salt level, and post that too please.

Properly shocking your pool will not cause damage to your equipment or your liner.

Burn out or Burn out Extreme?

One is Lithium Hypo the other is Cal-hypo.

Your CH is low enough that you can use cal-hypo if you choose to, for a while.

Just keep in mind that granular won't work 'better' than bleach - once it's in your pool, chlorine is chlorine is chlorine, and both forms are more expensive.

 

[indycreed]

I have lithium hypo on hand from before the bbb transition. Will make a trip to the store this morning to test salt.

 

[Bama Rambler]

When you've been shocking, have you made sure you've passed the OCLT (overnight chlorine loss test)? (1ppm loss overnight & .5ppm CC or less)
If so, shock it again and hold it at 24ppm FC until you pass the OCLT two nights in a row. If you let the FC drop during the day you lose ground on whatever is in there.

How many swimmers are there in the pool on a regular basis and what's their age range?

 

[indycreed]

The last time I shocked, I didn't lose any overnight and the cc was less than .5. That's why this is really irritating me.

I don't generally have a lot of swimmers in the pool. Mostly my son (12) and a friend of the same age, and my husband and I.

 

[Bama Rambler]

I asked, because last year we had an owner that was having a very high chlorine demand and come to find out it was because the kids were not following the "No P in the ool" rule. It's very odd to have to shock ever, let alone twice in four weeks without something significant going on.

You don't happen to live near where they're spraying crops do you?

 

[indycreed]

I live near cornfields, so there could be some of that going on.

Just got back from pool store to check salt. Level according to them is 1320. Tds 2160. Phosphates (for the fun of it) 3000.

 

[duraleigh]

Indy,

At the risk of being a complete bore, I want to go back to some basics to simplify your issue.

Chlorine gets consumed by two things.....organics in the pool and sunlight.....that's it.

Obvously, you eliminated the sunlight when you did the overnight FC loss test so the only thing that remains is organics in your pool. A loss of 2ppm indicates the need to shock.

The above statements are pretty much a "Universal Truth" for all of us that have pools. So far, nobody has a pool that is exempt from these ideas. Very frequently, peripheral issues come into play (bather load, testing errors, etc.) which tend to mask these basics but the basics always apply.

Shocking correctly will kill the remaining organics and leave you a crystal clear pool. Bringing your FC up to 24ppm and HOLDING IT THERE until......
1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.
should end your problems.

I would explore the "no pee in the pool" rule with the kids. I'm not sure that much ammonia can cause as much loss as you are indicating but it could certainly be a contributor.

Summing up, disregard all the peripheral issues like salt, phosphates, fertilizer, etc and shock your pool according to the "How to shock your pool" article in Pool School.

 

[indycreed]

I'm an idiot. Pulled my pool light out and guess what I found? Yup, mustard algae. Weird, but I was kinda happy. At least now I can get rid of it.

I had stopped by the pool store to buy some scum balls. Manager says to be sure and check behind the pool light because he'd been seeing lots of mustard algae lately. Ding ding...