How much bleach per day is normal?

[pffinman]

From TF-100 Kit
FC 2
CC 0
7.5 < PH < 7.8
TA 100
CH 260
CYA 40

From Leslies Pool Store
FC 3
TC 3
PH 7.8
TA 100
CH 250
CYA 40
Copper, Iron, Phosphate - all 0

From another local pool supply store (BioGuard Analysis]
Saturation Index 0.1
FC 1.2
TC 1.2
PH 7.8
TA 118, Adjusted TA 92
Total Hardness 226
CYA 68
TDS 400
Optimizer Plus 6

I had been using Trichor tablets with an automatic Chlorinator and Cal-Hypo to shock. The water was slightly cloudy and shocking didn't seem to help. CYA was 130 ppm, after reading some info at this site I decided to try switching to bleach. I drained about 66% of the water from the pool and refilled to reduce the CYA level. Since then other than Clorox Bleach, the only thing I've put in the pool was 25 lbs of calcium chloride dihydrate.

The water is now clear. I've been adding 1 gallon of regular Clorox bleach each evening, which the pool calculator indicates will raise the Chlorine level about 3 ppm. When I test the water (before adding bleach) the next evening, the FAS/DPD test has been indicating FC=2 (+/- 0.5 ), CC=0, a little below the minimum listed in the Chlorine / CYA chart.

1. Is it normal to loose about 3 ppm Chlorine each day? Does this indicate I need to "Shock", or just need to add a litte more bleach each day?

2. It has been sunny, and the pool is in direct sunlight most of the day. For this location (south east Texas), would it take more or less bleach per day if I raise the CYA level and then maintain the higher Chlorine levels recommended by the Chrorine / CYA Chart?

Thanks for your help and this site.

 

[daniel00]

It is not usually normal to loose 3ppm per day. This usually means that you have somthing organic growing.

1. You will need to shock your pool and mantain those shock levels for a 24hr period, or until your fc only drops by .5-1ppm

2. Your cya levels look ok at 60-70 your fc should be at 7-8. If you up your cya it will take more chlorine to maintain that fc level.

Daniel

 

[chem geek]

Welcome to TFP! :-D

If we use your 40 ppm CYA as the accurate value, then having a higher CYA even with proportionately higher FC will usually have a lower absolute chlorine loss. So instead of having a minimum of 3 ppm FC with 40 ppm CYA, you could have a minimum of 5 ppm FC with 70 ppm CYA and end up with a lower absolute FC loss per day, perhaps 2 ppm or less. The reason for this apparently comes from extra shielding of lower depths by CYA itself and not just chlorine being bound to CYA.

As was noted by Daniel, having 3 ppm loss per day might mean that you have organics or nascent algae growth in your pool. You can tell for sure by Performing the Overnight FC Loss Test since that eliminates the effect of loss from chlorine breakdown by the UV in sunlight. If your overnight loss is much lower than 1 ppm, then your chlorine loss is mostly due to sunlight so the higher CYA (with higher FC) should help. If your overnight loss is high (even 1 ppm FC), then you've probably got things in your pool that you need to get rid of by shock levels of chlorine.

Given that you had some algae growth and never really fully shocked consistently to fully get rid of it, I suspect you'll need to Shock Your Pool to get ahead of the algae that is probably still in the pool even though it is no longer visible (the last bit of dead algae getting oxidized may not be visible but still consumes chlorine).

 

[duraleigh]

Welcome to the forum! :lol:

Given your southern latitude, full sun all day, and your current CYA level, I would not consider a 3ppm loss to be completely out of whack.

From discussions here on the forum a 2ppm loss seems about average for a very well kept, manually chlorinated pool.

Increasing your CYA will result in less FC consumption but I would suggest not increasing CYA over 50 or so in a manually chlorinated pool such as yours. The resultant need to increase and maintain the FC somewhat offsets the gain.

It's sort of a balancing act with no exact right or wrong answer. That you test and dose accurately is a big plus in allowing you to set the levels you prefer. It's also at the heart of BBB.

As chem geek indicated, the overnight FC loss test will be the key to telling you if you have organics consuming the FC rather than simply sunlight.

 

[Bama Rambler]

Just to give advice from similar experience. I get about 8 or 9 hours a day of direct sun on the pool and I lose about 2ppm per day, which equates to about 1½ quarts of 6% bleach per day. My CYA is 50ppm. When I started out I had a CYA of 35 and was losing about 4ppm per day. I slowly bumped the CYA up 5ppm at a time until I go down to losing 2ppm per day, which I consider perfectly acceptable. I will qualify this by saying that 50ppm CYA is as far as I've gone. I've been tempted to try 60 but since I'm only adding 48oz of bleach per day I haven't gotten brave enough to do it. I also now use the liquidator instead of manually pouring in bleach and it's a lot easier.

 

[frustratedpoolmom]

It is not usually normal to loose 3ppm per day. This usually means that you have somthing organic growing.

1. You will need to shock your pool and mantain those shock levels for a 24hr period, or until your fc only drops by .5-1ppm

2. Your cya levels look ok at 60-70 your fc should be at 7-8. If you up your cya it will take more chlorine to maintain that fc level.

Daniel

Daniel, please check your PMs - upper left corner.

 

[257WbyMag]

Yep, just check an overnight FC loss as suggested. If your FC holds to within 1 ppm over night, you may then consider adding a little bit more CYA to your pool, maybe 10 ppm. You are essentially on the coast and things are only going to get warmer and the sun is going to get more intense. You want to be able to use the pool without the FC dropping below minimum.

 

[pffinman]

Thanks for all the advice, I'll run the Overnight FC Loss Test this evening.