Is there anything on what to expect for normal demand/use of chemicals?

[twesterd]

I have about a 13,000 Gal in-ground gunite pool. The weather here is about 100 degrees every day. I run my pool filter a lot... about 10 hours day. When my pump runs, it circulates the water extremely well. So, well it ripples the water and probably adds aeration. Assuming the water is crystal clear, and balanced, what would be a typical normal consumption of chemicals (I.e. 8.25% bleach, muriatic acid, etc)?

Is there an existing chart of some sort? What I am asking... should I expect to use 1, 2, 10 gallons of bleach per day/week. What is typicial/normal usage of chemicals? I know there is large variation, but there should be some form of normal, right?

 

[jblizzle]

You typically need 2-4ppm of FC added per day, use PoolMath to calculate the amount of bleach that requires. No way to estimate anything else.

 

[kcindc]

Best to keep your initial questions in one thread. What may seem like un-related questions can help us put things in context.

I read another post of yours which you said your CYA was 70. That seems a little high to me since it doesn't appear that you are using a SWG, but I don't live in your location. Hopefully someone from your part of Texas will chime in on their CYA recommendation.

I was really surprised at the amount of chlorine you were using. I suggest (and others have also mentioned this) that you order the FAS-DPD test it uses powder and is much more accurate.

You can order the FAS-DPD test here:
Just the FAS-DPD which is $26
http://tftestkits.net/FAS-DPD-Chlorine-CC-s-test-p47.html

Or you can get the full kit (great value) for $68.
http://tftestkits.net/TF-100-Test-Kit-p4.html

Once you get your FAS-DPD. I would raise your FC to shock level for you CYA and perform and OCLT (you will need the FAS-DPD to this test):
http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

It is way too variable to say your pool will use X amount of this and that. Weather (temp humidity), source of FC (bleach, SWG, pucks, etc.), debris from trees and plants, pollen, dust, swim load, sunlight, dogs, pool size, pool equipment, pool run time, extra aeration from waterfalls, etc.

For a few years, I used 1 jug of 8.25% bleach a day, but now I am down to 3/4 of a jug since I removed some trees. Daily testing and logging of your results and what you add will help you see patterns and will help us help you figure out if something is out of whack.

 

[twesterd]

I thought this question was not related. I asked if chlorine could be "old" or be somewhat bad (I.e less than the stated percent of chlorine) when new. I asked this because I added a LOT more chlorine than normal

NOTE I have ordered the FAS-DPD and the speedstir.

ALSO NOTE: I switched back to Chlorox and the demand went back down to normal so I really believe I got a bad batch of bleach. I can't know for sure. My pool may just have needed a bunch of bleach and the timing was weird. Again, how can I know for sure? I planned to finish the other thread with all the results when I get the FAS-DPD kit.

I asked this question separately, not to confirm or deny whether I got bad bleach but just to see if there is a sense of what a normal demand or use should be regardless of the other thread. I didn't want it to be about something weird, but rather what is normal

I really appreciate you letting me know you use 1 jug per day, now down to 3/4 jug per day. My pool normally uses about 1/2 gallon per day. I usually dose it up once per week to slightly shock it. About once a month I shock it to 10 ppm or more. I also add more: (1) when it rains hard, (2) after really windy days where debris gets dumped into the pool, and (3) heavy use

and... thanks!

 

[twesterd]

FYI: My CYA is high because my wife wanted to use our pucks. She loves the smell of chlorine, put as many pucks as she could fit in the chlorine float, and was picking up the float and dropping it back in the water repeatedly. Before I knew it, the CYA skyrocketed. I swear, I think she wants the chlorine to normally be 10 ppm.

We have drought going on here, so draining half the pool and refilling is not an option. I drained some water and refilled some (about a fifth of the water). Banned pucks except for very limited vacation or away time and now am reducing it by splash out and evaporation and refilling. My intent is to lower it to about 30 ppm. I have no idea how quickly that will happen. It is 80-90 ppm right now and I don't think its so high that I should panic. Maybe it will go down in a week or two, maybe months, but it should go down.

 

[svenpup]

CYA will go down slowly with backwashing (and very slightly from oxidation) but you have no reason to believe that it will go down significantly in a week or two.

You joked about your wife wanting the FC to be 10ppm, but with CYA = 90 your target FC should be 10. :lookhere: Chlorine CYA Chart

 

[twesterd]

The weather is 100 degrees here. A lot of water evaporates. The CYA was 160 two weeks ago when I drained 1/5 the water. It lowered to about 125 from that. So, its much quicker than you think since it went from 125 to about 85 in a couple of weeks. There is also a lot of splash out (many of us play a lot)

NOTE: There is a water shortage here and I do not have the option to drain and refill. I see why you are recommending to shoot for 10 ppm every day, but the water is so clear I can see the grooves in my toenails at the bottom. There is no algae. There is no odor. There is no staining of any kind. I keep it between 2-4 ppm and its fine. I raise it to 8 ppm once a week and to 20 ppm or more once a month. I do plan to super shock it this week. I think the hot sun makes it almost impossible to keep it at 10 ppm for any length of time; especially, when I don't have a particularly deep pool (5.5 feet).

 

[twesterd]

Here is what the pool steps look like right now:

 

[jblizzle]

I am not sure if you were implying that the high evaporation is helping you lower the CYA. If so, that is simply not true. The CYA will not drop due to evaporation, just like salt level will not drop with evaporation. As the water evaporate, the concentration in the pool goes up and then when you add water back in, the concentration drops back to where it started.

 

[twesterd]

Man, several times a write a response and hit post and the it never posts.

- - - Updated - - -

I did not mean evaporation removes CYA. I meant I have lots of kids and adults playing and they splash lots of water out of the pool. In addition, evaporation does remove a significant amount. Combined, it means I add a lot of water each week, that added water dilutes the CYA and lowers the number.

 

[Suley]

To answer your original question, every pool has it's own character and you will figure out how much of what chemicals it needs in a few seasons. This will change with a change in bather load, splash outs and aeration (splashing around). Splash outs remove CYA, sunlight on pool burns off FC, splashing in the pool raises pH. By how much or how little can only be told by maintaining the pool consistently for a while.

 

[H-12 1/2 Mike]

We have a 16K gal pool in North Texas and we average 48 oz of chlorine per day with very low bather load. Our water is tested and adjusted each day Last Sunday after 3" of rain it took 128 oz of chlorine that day to get it back to normal.