# Thread: Going through 2 bottles a day... normal?

1. ## Going through 2 bottles a day... normal?

I suppose since the pool is in the sun from about 8AM to 8PM is the reason I'm going through so much. On days when it's cloudy, I only need to put one in.

~27k gallons, every night, I measure when I get home and the FC is about 4, sometimes as low as 3.5. My CYA is 50, and CC's always test out at < .5 or 0

According to the calculator, a 121oz of 8.25% equates to raising FC by 3 (which I will prove below), so by putting in 2 bottles, FC should have raised it up to about 10 if it measures 4 in the evening.

Last night I put in 2 bottles, and at 10pm, the level was 8. This morning it measured 7.5. I put another bottle in, waited an hour, tested again, and it's 9.5, so that verified 1 bottle indeed brought it up by 3. That also tells me the level must have been at 2 before I put them in :O

According to this, I'm losing 6 ppm each day when it's hot & sunny. Does this sound normal?

Water is crystal clear, and warm.

CC < .5
Ph is 7.4
CYA 50

2. ## Re: Going through 2 bottles a day... normal?

6 ppm per day sounds like too much to me, in fact, if I was using over 3 ppm per day I would be concerned that I had something growing in a light fixture, main drain, ladder, etc.

3. ## Re: Going through 2 bottles a day... normal?

I can go through 4ppm per day if the cover is off, in the sun, and a few people are using the pool- if a lot of people were in, I could see going through 6ppm, though this is only a guess. I don't get too concerned because on days the cover is on all day I only go through .5 - 1ppm.

Pool is in the sun 7am-7pm

4. ## Re: Going through 2 bottles a day... normal?

Originally Posted by ewkearns
6 ppm per day sounds like too much to me, in fact, if I was using over 3 ppm per day I would be concerned that I had something growing in a light fixture, main drain, ladder, etc.
But it looks like he's not really losing much FC overnight - wouldn't that indicate that there's likely not something growing in there?

5. ## Re: Going through 2 bottles a day... normal?

Originally Posted by lvrpl
But it looks like he's not really losing much FC overnight - wouldn't that indicate that there's likely not something growing in there?
While I would usually agree, it's obvious that the FC has repeatedly dropped below the recommended minimum for the CYA level.

If this was my pool I would elevate the FC to shock level (20ppm) and do a proper OCLT (minimum of 8 hours with pump running & no cover) to validate.

Dom

6. ## Re: Going through 2 bottles a day... normal?

Depends on where you live. I lose about 6-7ppm FC per day with a CYA of 50 (it's really mid 40's but I always round up). If you've been having the dry days with almost not break in sun like we have been in TX, I don't think it's totally off the charts. Test FC/CC after sundown and then again in the morning. If you lose more than 1ppm FC and/or have more than .5CC ( I prefer 0) you have something organic in there using it up. And should SLAM sooner rather than later. If all your other numbers are good and you're only losing it during the day, then it's likely the sun and swimmer load.

I would definitely approach it like Dom said.

7. ## Re: Going through 2 bottles a day... normal?

Originally Posted by domct203
While I would usually agree, it's obvious that the FC has repeatedly dropped below the recommended minimum for the CYA level.

If this was my pool I would elevate the FC to shock level (20ppm) and do a proper OCLT (minimum of 8 hours with pump running & no cover) to validate.

Dom
Remembering this little tidbit is how I caught my possible algae bloom before I could see a difference in the water. If FC is not holding overnight, something is there and will likely get worse. Catch it before you can see it in your pool.

8. ## Re: Going through 2 bottles a day... normal?

Thanks for the replies.

The replacement board for my swg came in today. I could run the bleach up to shock level tonight and check again in the morning, then go back to swg mode

9. ## Re: Going through 2 bottles a day... normal?

It has been hot, several 3 digit days... it's cooled a bit, but will be hot again on Sunday.

I measured tonight, and it's down to 4. I bumped it up to 16 and put the pool cleaner in, and will measure again tonight and in the morning, then set the thing to come on mid-day for the SWG to keep it from falling so much.

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