Hi all. this is my first post so please forgive me if I am asking a lot of questions that have been answered many times over in this forum. I have had chlorine demand issues for last couple of years. I have probably spent $5000 on chemicals the last 3 years alone at a very reputable local pool store. I have tried doing all of the right things...we vacuum and clean pool a couple times a week. We take water samples to the aforementioned pool store weekly to maintain balance and add whatever they tell us. The pool gets clear and the PH and ALK is usually in good levels but the FC is always around 0. Just 4 days ago I took a sample in and the PH was 7.4, TC was 5.5 and FC was .6. They had me add 25 lbs of shock which I did. Today the water looks clean(slightly cloudy) but I can see algae starting on shallow end and test strip shows 0 chlorine. I am at wits end. I have heard replacing the water is only way to really cure this problem, but I don't want to do that until I can replace the liner and have bottom resurfaced so big $$$. Is it possible to cure any chlorine demand problem? I have been looking at forum and looks like I will be ordering a new test kit for starters. Any other suggestions??? Thank you!
Chlorine demand for years
- Thread starter Poolrunsme
- Start date
Welcome to tfp, Poolrunsme 
You come to the right place! We can help and as you poke around on the forums you will find many threads that start out somewhat similar to yours. However, until we know what is in your pool, we won't know if it can be done without a partial drain/refill. So often following pool store advice causes the eventual need to drain/refill. The TFP methods, if followed correctly, will generally not require drain/refills in the future...but it may be required to get started.
First thing you need to do for us to really help you, is to get your own appropriate test kit. Read this pool school article: http://www.troublefreepool.com/pool-school/pool_test_kit_comparison Many of us have the tf-100, best bang for buck.
Saying that, you could post if any additional test results were done like cya, TA, and CH. Also, see this pool school article: http://www.troublefreepool.com/pool-school/read_before_you_post
There is a lot of good information in pool school and the link is always near the top right.
You come to the right place! We can help and as you poke around on the forums you will find many threads that start out somewhat similar to yours. However, until we know what is in your pool, we won't know if it can be done without a partial drain/refill. So often following pool store advice causes the eventual need to drain/refill. The TFP methods, if followed correctly, will generally not require drain/refills in the future...but it may be required to get started.
First thing you need to do for us to really help you, is to get your own appropriate test kit. Read this pool school article: http://www.troublefreepool.com/pool-school/pool_test_kit_comparison Many of us have the tf-100, best bang for buck.
Saying that, you could post if any additional test results were done like cya, TA, and CH. Also, see this pool school article: http://www.troublefreepool.com/pool-school/read_before_you_post
There is a lot of good information in pool school and the link is always near the top right.
Welcome!!
You have algae. The chlorine is doing its job and killing some of the algae, but not all of it. The algae that doesn't die multiplies, and you do it again the following week. So your "chlorine demand" isn't a mystery, it's all happening the way it should.
Follow linen's advice, then with the help of the wonderful users on this forum, we will eliminate your algae and give you clear, sparkly water all summer (and I can pretty much guarantee that if you buy a good test kit and follow our advice, your chemical bill will be a fraction of what it was in the past - see my signature for an example).
You have algae. The chlorine is doing its job and killing some of the algae, but not all of it. The algae that doesn't die multiplies, and you do it again the following week. So your "chlorine demand" isn't a mystery, it's all happening the way it should.
Follow linen's advice, then with the help of the wonderful users on this forum, we will eliminate your algae and give you clear, sparkly water all summer (and I can pretty much guarantee that if you buy a good test kit and follow our advice, your chemical bill will be a fraction of what it was in the past - see my signature for an example).
Things are a bit hectic this time of year so please forgive me if I am brief here,
As Linen said, we hear this store a lot (multiple times per day sometimes this time of year), the thing you need to remember is the pool store is in business to sell you Chemicals, the people there have been taught how to treat a pool using the most chemicals possible, this is not always the fault of the person you interact with, even well meaning pool store owners get most of their information from their supplier's sales reps, who again want to sell as many chemicals as possible.
Our interest here is to maintain a pool in good sanitary condition, and secondarily do that as cheap as we can.
In that end knowledge is key, this means you need one of the suggested test kits from pool school, I personally strongly suggest the TF-100 in my signature link over the K-2006 it cost a little more but is a MUCH better bargain in the long run.
So if you have decided to trust us get a kit on order, then start reading pool school, and when you get good test numbers from the kit we can get started solving your problem
Ike
p.s then go back and read pool school again, link in the upper right of every page here
As Linen said, we hear this store a lot (multiple times per day sometimes this time of year), the thing you need to remember is the pool store is in business to sell you Chemicals, the people there have been taught how to treat a pool using the most chemicals possible, this is not always the fault of the person you interact with, even well meaning pool store owners get most of their information from their supplier's sales reps, who again want to sell as many chemicals as possible.
Our interest here is to maintain a pool in good sanitary condition, and secondarily do that as cheap as we can.
In that end knowledge is key, this means you need one of the suggested test kits from pool school, I personally strongly suggest the TF-100 in my signature link over the K-2006 it cost a little more but is a MUCH better bargain in the long run.
So if you have decided to trust us get a kit on order, then start reading pool school, and when you get good test numbers from the kit we can get started solving your problem
Ike
p.s then go back and read pool school again, link in the upper right of every page here
Thanks for the quick replies, I think I am going to like it here 
I have just ordered a TF-100 test kit so I should have that early next week and I will run a complete gamit of tests and post the results. Have a great weekend...Special thanks to our VETs!
I have just ordered a TF-100 test kit so I should have that early next week and I will run a complete gamit of tests and post the results. Have a great weekend...Special thanks to our VETs!Hi again...I just finished testing with my brand new TF100 test kit. First let me say this kit amazing! Currently the pool looks good. It is pretty clear and no noticeable algae growth. We have had a lot of rain in the last week but it is very hot and humid now in the northeast. My pool temp is 84 degrees. I have only filled chlorinator with chlorine tablets 5 days ago. I have not added any other chemicals to the pool for about 11 days when I last added 25 lbs of CLC (shock) as recommended by my pool store. Here are my test results:
FC=.5
CC= 1.0
TC= 1.5
TA=230
CH= 210
CYA= 100+ (it was about 1/8" below 100 mark on CYA tube.)
PH= 7.5
I am actually surprised that it is registering any chlorine at this point. The only thing I have done differently this season compare to last couple was to use 5 gallons of liquid chlorine when I first opened it and have cleaned the filter two times. I am not sure what I should add to the pool now and for regular maintenance? Thanks much for your suggestions.
FC=.5
CC= 1.0
TC= 1.5
TA=230
CH= 210
CYA= 100+ (it was about 1/8" below 100 mark on CYA tube.)
PH= 7.5
I am actually surprised that it is registering any chlorine at this point. The only thing I have done differently this season compare to last couple was to use 5 gallons of liquid chlorine when I first opened it and have cleaned the filter two times. I am not sure what I should add to the pool now and for regular maintenance? Thanks much for your suggestions.
Good choice on the test kit 
Well ... all the tablets have caught up to you. They add chlorine and stabilizer, the chlorine is consumed and the CYA builds up. Yours is WAY too high and thus you now need to replace at least 50% of the water and then stop using tablets and switch to liquid chlorine and then follow the Shocking Your Pool PROCESS.
You may want to do the CYA test again starting with a 50/50 mix of pool and tap water, then add the reagent and double the reading to get a better idea just how high the CYA is.
Have you been reading Pool School to understand the chemistry?
Well ... all the tablets have caught up to you. They add chlorine and stabilizer, the chlorine is consumed and the CYA builds up. Yours is WAY too high and thus you now need to replace at least 50% of the water and then stop using tablets and switch to liquid chlorine and then follow the Shocking Your Pool PROCESS.
You may want to do the CYA test again starting with a 50/50 mix of pool and tap water, then add the reagent and double the reading to get a better idea just how high the CYA is.
Have you been reading Pool School to understand the chemistry?
Poolrunsme said:
How'd I miss this thread? This must be a record for being Pool-stored.
So... you ordered a TF100... you should be ashamed. That store owner's kid is about to lose his free ride to college. Don't you feel awful?
poolrunsme,
Sorry, I am late to this thread but get some chlorine in your pool today. Even though it looks like you'll be draining, you need a bit of protection NOW.
2-3 gallons of clorox should hold you for now but you are begging for an algae bloom not having chlorinated in 11 days.
Sorry, I am late to this thread but get some chlorine in your pool today. Even though it looks like you'll be draining, you need a bit of protection NOW.
2-3 gallons of clorox should hold you for now but you are begging for an algae bloom not having chlorinated in 11 days.
I was afraid that a drain would be needed. I redid the CYA test as recommended and am getting close to 160! I used 50/50 of pool and tap and it was close to 80. I guess I need to start figuring how many pool water trucks I will need...and yes I think me pool store will be taking a hit this year!
Make sure you only drain down to 1 foot depth (or greater) in the shallow so that your liner does not move. That probably means you will need multiple drain/refills since you need to drain about 70% of your water to get down to the recommend cya level of 30-50 ppm.
Really? That is about how much I have drained at closing last couple of years. I do not see how that is possible? I need to have water trucks deliver the water...I would practically have to drain while trucks are coming. Would seem like I am wasting new water, no?
You could do this in phases (partial drain/refill) if you wanted to and just maintain a rather high FC level in the meantime. At 160 ppm FC, you need to maintain a minimum of around 12 ppm FC to prevent algae growth under worst-case conditions (i.e. lots of phosphates and nitrates in your water). You might be lucky enough to go lower, but no guarantee. As the CYA level drops, you can lower your target FC level. Basically, your target is to have the minimum FC be at least 7.5% of the CYA level.
This may sound like a high chlorine level, but it really isn't since most of the chlorine is bound to CYA doing essentially nothing except being a reserve of chlorine. The active chlorine level in your pool will still be very low -- the same as just 3 ppm FC with 40 ppm CYA. And with the high CYA level, you may only lose 2 ppm FC per day, maybe even a bit less.
To prevent the CYA from climbing, you'll need to use chlorinating liquid or bleach as your primary source of chlorine.
This may sound like a high chlorine level, but it really isn't since most of the chlorine is bound to CYA doing essentially nothing except being a reserve of chlorine. The active chlorine level in your pool will still be very low -- the same as just 3 ppm FC with 40 ppm CYA. And with the high CYA level, you may only lose 2 ppm FC per day, maybe even a bit less.
To prevent the CYA from climbing, you'll need to use chlorinating liquid or bleach as your primary source of chlorine.
As chem geek said, after this drain and refill, if you stop using trichlor and dichlor (in excess) to chlorinate, you will stop having to drain and refill the pool periodically. Take a look at this pool school article: http://www.troublefreepool.com/pool-school/types_chlorine_pool
I am thinking we might just limp along this season using liquid chrlorine/bleach and then do the drain refill at closing time. This way I would only have to fill it to about a foot depth in shallow end so might save me a couple of trucks of water at $350 a piece. Any pitfalls with that plan?
While often talked about, I've not seen a documented thread where somebody has done it. I think the tarp price is prohibitively expensive. The idea is to spread a huge tarp over entire pool, put fill water on top of tarp, and drain from underneath it. Effectively keeping new and old water separate.
I assume there is a good reason you can't fill from a hose?
I assume there is a good reason you can't fill from a hose?
I have a well so I am afraid to run my well pump long enough to fill my pool(about 40000 gallons.
Poolrunsme said:
In the Hudson Valley, I would think your wells are pretty robust. (I'm guessing your geology is similar to what I see here in north-central NJ.) If the water is good pool quality (low in iron and other metals) and not too bad on calcium, consider doing 2-3 feet every week or so. I'm thinking 5-6k gallons or so, equivalent to a donut pool, is probably no sweat in your area unless you have a very poor well. By mid-summer you could put a good dent in your CYA.
Look at http://www.poolcalculator.com/ and plug in (at the bottom) your length and width and one foot of depth. That will tell you how many gallons in each foot of your pool (until you get to the bottom in the shallow end, obviously). We have certainly had enough rain lately making up for the dry Spring.
Actually, a fellow thread member used this "tarp" draining method here -- he was in Florida with a high water table and a vinyl pool as I recall: Here's the thread - think it was a relatively inexpensive approach:
foreclosure-swamp-in-pensacola-florida-t54326-60.html
However, depending on the delivery rate of the truck, etc., you might want a trash pump to speed up or synchronize the drain/fill ratios
I know water trucking is expensive -- if you were committed to keeping your FC at an adequate level all summer (min 12 FC for size and CYA level) you might be ahead, but by the time you factor in the bleach cost for 40,000 gallons and the general rule of thumb that you can count on 1/3 to 1/2 your daily dose dropping each day from sun etc., you might end up spending almost as much. You'd also have to figure out how much chlorine your pool is "consuming" during the day while you're gone, because to fight off algae in your situation, you'll have to dose ABOVE that level to make sure you never fall below the minimum.
At any rate, you're on the right track and have received good guidance. I say let the pool store kid save his own money for college
foreclosure-swamp-in-pensacola-florida-t54326-60.html
However, depending on the delivery rate of the truck, etc., you might want a trash pump to speed up or synchronize the drain/fill ratios
I know water trucking is expensive -- if you were committed to keeping your FC at an adequate level all summer (min 12 FC for size and CYA level) you might be ahead, but by the time you factor in the bleach cost for 40,000 gallons and the general rule of thumb that you can count on 1/3 to 1/2 your daily dose dropping each day from sun etc., you might end up spending almost as much. You'd also have to figure out how much chlorine your pool is "consuming" during the day while you're gone, because to fight off algae in your situation, you'll have to dose ABOVE that level to make sure you never fall below the minimum.
At any rate, you're on the right track and have received good guidance. I say let the pool store kid save his own money for college
Thanks for posting that link, I missed that thread!Swampwoman said:Actually, a fellow thread member used this "tarp" draining method here -- he was in Florida with a high water table and a vinyl pool as I recall: Here's the thread - think it was a relatively inexpensive approach:
foreclosure-swamp-in-pensacola-florida-t54326-60.html
However, depending on the delivery rate of the truck, etc., you might want a trash pump to speed up or synchronize the drain/fill ratios
I know water trucking is expensive -- if you were committed to keeping your FC at an adequate level all summer (min 12 FC for size and CYA level) you might be ahead, but by the time you factor in the bleach cost for 40,000 gallons and the general rule of thumb that you can count on 1/3 to 1/2 your daily dose dropping each day from sun etc., you might end up spending almost as much. You'd also have to figure out how much chlorine your pool is "consuming" during the day while you're gone, because to fight off algae in your situation, you'll have to dose ABOVE that level to make sure you never fall below the minimum.
At any rate, you're on the right track and have received good guidance. I say let the pool store kid save his own money for college