Chlorine Usage

[MaxAcceleration]

So I've been consistently using about 4ppm of chlorine per day in my pool and I was wondering if that's normal?

cya: 45
ph: 7.5
alk: 175
temp: 89

The pool calculator says I need to maintain a 4-8 with my current cya so I target 6 - each morning adding a full gallon of chlorine (pool calc says 112oz but I just add the full 128). By the next morning its down to between 1.5 - 2ppm, and I add another gallon to boost it back up to 6. We have two kids and two adults so were not having huge pool parties.

I did the OCLT and lossed less than .5 and the pool looks great, no cloudiness and no algae.

So yesterday morning I covered it with a huge tarp (not a solar cover) to see how much the sun is eating and added my usual gallon. When I checked this morning I had a 5ppm! So the sun must be eating about 4ppm per day.

My pool is in full sun most all the day, and my chlorine cost is $11.33 per 4 gallon case of 12.5% bleach. So I'm spending about $3 per day on chlorine. Seems like a pain to have a case only last four days though. That's a lot of hauling of chlorine from the pool store. Playing devils advocate, it almost seems easier to just use pucks and get rid of half my water each year (I'm on well water so there is no bill for water other than the electricity my pump uses). Cause right now I'm maintaining daily with chlroine / testing, -vs- weekly with the floater.

Also, should I consider covering it daily when the pool isn't in use? Seems that would cut my daily chlorine down to 25oz so I'd get 5 full days out of a gallon.

Thanks in advance for the advice.

 

[woodyp]

Covering it is good to reduce chlorine loss due to the sun. My pool loses 3.5-4ppm daily in full sun. No problem with pucks if you watch that too high of level of cya that is manageable if you don't mind draining and refilling. You'd still need to test it though.

 

[duraleigh]

You could certainly do what you are thinking.

You seem to be losing just a bit too much chlorine (than average) so, before that, I would suggest re-checking CYA and make sure it is 45...50 would be even better but the precision of the test is only + or - 10 ppm.

The whole concept of BBB is managing your pool the way that's best for you (and understanding the side effects of what you add to your pool).

Full time pucks will raise the CYA VERY quickly in the middle and late summer so you'll have to test often and be cautious, but you can try that if it suits you better. (use the poolcalculator to see the effect of adding chemicals at the bottom of the screen.

 

[ping]

I would put in another 10 ppm worth of CYA and see if that helps. If you don't mind dealing with the cover, that seems to solve the problem also.

 

[chem geek]

If you have not already done so, check your overnight chlorine loss just to make sure that the large loss is indeed due to sunlight and not something else in the pool. Though our criteria for shocking is <= 1 ppm FC overnight, at normal FC levels you shouldn't see more than 0.5 ppm FC drop overnight unless something is amiss. Our pool if not used and the opaque cover on will lose around 0.7 ppm FC over 24 hours so overnight it's less than half that amount and this is with the water at 88ºF (the loss rate is dependent on temperature so is even lower at cooler water temps).

 

[jblizzle]

Just to add, since it does not appear to be pointed out. The most important thing to remember is that the 4ppm is a MINIMUM, so you should not be targeting 6ppm if you are losing 4ppm each day. You should be targeting 8-9ppm to make sure it stays above 4ppm.

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