Where is my chlorine going?

[wgj10]

We have a new salt water pool built in the last few months, first fill about a month ago. We're having trouble maintaining chlorine levels even on very cloudy days. The water looks crystal clear to me with no discoloration. No algae visible to me. Our T-15 has been running two days at 50%, though yesterday we switched it to super chlorinate for most of the day. Filter runs about 12 ours. Two nights ago I dropped in 128 ounces of 7.65% chlorox, and had 4 dichlor pucks in the skimmers most of the day. Next morning Chlorine was at .1ppm. Yesterday we put in 4 bags of smart shock, 39% dichlor, at 7:30 pm the chlorine reading was over 3, this morning its back to close to zero. This was overnight, and during the days we've had nothing but clouds and rain. Is it possible I have that much algae or organic matter when the water looks, feels and smells perfect? Any other explanation?

SI -.5
Total chlorine <1
free chlorine .1 ppm
PH 7.5 (using low and slow when it inches up)
total alkalinity 90 (been adding balance 100)
total hardness 120 (been adding balance 300)
Salt 3100
CYA 30
about 44,000 gallon pool, saltwater

Pool store appears to have tested for some algaes and slimes with no readings as part of their comprehensive test. There is some residual dirt I can see from the construction when I scrub that we've been filtering and vacumming, but seems relatively little. Any ideas? what gives?

 

[tim5055]

Only two things make the chlorine go away, the sun and organic matter in the water.

To follow the pool care methods taught here you need to arm yourself with the knowledge and tools necessary to care for your pool.

The tools are not limited to the brushes, vacuum hoses and other stuff you use around the pool, but include the most important item - one of the recommended test kits. You need this NOW. You can buy a kit at a pool store, but again the pool store kits generally won't cut it. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. All the recommended kits contain that test while very few other kits do. Most of us think the TF100 is the best value as it contains more of the reagents you use the most.

The knowledge is condensed in the Pool School link at the top of every page. You need to start reading the Pool School and you will quickly realize that the pool store is moving money from your bank account to theirs quickly. Products like "low and slow" perform no better than the "generic" replacements that are available. In some cases the generic is better because it doesn't contain a bunch of added magic potions to allow them to jack up the price.

It is a great community here, but we do ask that you read and try to understand the information being taught. Questions are always welcome and folks will try to direct you and teach you the methods.

You are lucky that you found TFP early while your water is still clear and most of the money is still in your wallet.

So, step one is to order your test kit and take control of your pool!

Step two is to stop using ANY solid chlorine products until you can test the water yourself. The test that pool stores mess up the most is the test for CYA (also know as stabilizer) and this is critical. The more CYA you have the higher you have to keep your chlorine level in the pool to maintain the same sanitation.

Welcome to TFP!!

 

[DogsHouse_MyPool]

You aren't adding enough chlorine to the pool. I did some estimates for a 44k gal pool using the PoolMath page (link at top of the forum pages). I too have a T-15 cell on my pool. Your T-15 cell will only produce 1.4 Lbs CL per 24 hours of runtime. Assuming a typical daily loss of 3ppm CL (swag), you need to produce 1.125 LB CL daily. That equates to running the unit at 80% for 24 hrs per day, or 100% for 19.25 hrs per day.

If you use 8.25% bleach to add 6ppm CL to load up the pool, I would expect you should be able to maintain the 6ppm with the swg, or at least keep it close, using the run-time estimates above. it will take approximately 2.5 gal of bleach to create the 6ppm start off point.

 

[DogsHouse_MyPool]

BTW, welcome to the TFP forum! I will tell you that you need to decide up front how you are going to manage your pool. If you are going to use the TFP method, you need to go all in and get that required and approved test kit ASAP. I would not hesitate to get the TF-100 with the XL option. You are going to be running quite a few of the CL tests, as you learn how to operate your pool, and its equipment. If you are able to stay ahead of the CL as you start to use your wonderful new pool, the worse thing that happens is you some extra CL test reagent that you will use over the winter or early next year. Not a big deal IMHO. If you cant stay ahead of the algae, as I will submit you may not be fully prepared and educated at this point, there is a good chance that before you are All In with the TFPC method, you will get some green in your pool, and you will need the extra test reagents. I feel so strongly about this, I would recommend you get expedited delivery of the test kit.

Otherwise, you are at the mercy of the "professionals" and their shot gun approach to clearing your pool, using expensive chemicals/algaecides that you will be spending top dollar for. This method is also reactionary to your problems instead of the TFPC methods proactive approach.

 

[wgj10]

Thanks guys. I already have the Taylor k-2006 and 1766 tests ordered. While waiting for them to arrive I've been using a barrage of different strip tests, a reagent drop test for chlorine/ph, and testing at the pool store. I've been reading the forum info for a few weeks and using the pool math calculator though admittedly I have not come near to reading everything. I have not done a slam and was hoping not to. Just flummoxed as to why the chlorine is burning off with no visible signs of algae anywhere. Wondering if it has to do with the little dust clouds that still aren't completely gone when I scrub. Thanks again, and the info on how much chlorine my t-15 can generate is particularly helpful.

 

[tim5055]

Thanks guys. I already have the Taylor k-2006 and 1766 tests ordered. While waiting for them to arrive I've been using a barrage of different strip tests, a reagent drop test for chlorine/ph, and testing at the pool store. I've been reading the forum info for a few weeks and using the pool math calculator though admittedly I have not come near to reading everything. I have not done a slam and was hoping not to. Just flummoxed as to why the chlorine is burning off with no visible signs of algae anywhere. Wondering if it has to do with the little dust clouds that still aren't completely gone when I scrub. Thanks again, and the info on how much chlorine my t-15 can generate is particularly helpful.

I think DogsHouse_MyPool covered where your chlorine is going fairly well. I won't swear you don't have something growing, but just remember just because you see something on the bottom of the pool it doesn't always have to be algae. As an example I've been trying to figure out small stains that keep popping up around my pool for months. I kept going through all the options, algae, mustard algae, metal staining, you name it I've thought of it. Turns out it is a little simpler - when we go to bed at night I have a couple of frogs that think it is their pool and sometimes they leave me little presents on the bottom. I catch them when I can and relocate them to the lake down the street but there are more of them than I can catch, or the one or two know their way "home".

 

[DogsHouse_MyPool]

If you decide that this site is for you, you may as well get your profile signature updated with all the pertinent information of your pool, so we don't have to search out or ask for your information when we try to help.

You also need to go to PoolSchool! Again, you can find the link at the top of the forum pages. There you will learn about the recommended chemistry for your SWG pool and the pitfalls of using dry chlorine products (dichlor/trichlor) to try to maintain your pools chemistry. I'm not saying it cant be done, in fact it can, but I don't recommend it for the novice operator. The basic chemicals used by the TFPC (also called BBB) are used and preferred because they tend to only impact the specific problem you are trying to address:

• muriatic acid to lower pH

• aeration (yes free air), washing soda or borax to raise pH

• bleach to add CL (or swg in your case)

• baking soda to raise TA

• stabilizer to raise CYA (the only item you typically need to get at the pool store or in the pool aisle at your favorite discount retailer)

• calcium chloride to raise Calcium

Even the salt for your swg can be had cheaper than at the pool store. You can usually find water softener salt cheaper than pool salt at the pool store, (but not rock salt / deicing salt)

All this will add up to saving money on supplies, by not adding (expensive) chemicals you don't need, and not solving one problem, only to create or contribute to another. Yes, you need to spend about $100 on test reagents per year. I think you will save that many times over

• by saving on the required maintenance items above

• not having to buy specialized (read-over priced) pool chemicals meant to fix a problem you want to avoid in the first case.

• gas running to the pool store to get that "free water test"

You will probably also find there is not much credence placed in that "free" advice at the pool store. Often, we find free testing and advice to be inadequate, inaccurate, and believe it or not, wrong. Another reason we insist on doing your own testing with an approved test kit.

So I recommend you get some CL in that pool, then settle down to PoolSchool over the next couple days, to see if you can lay a solid foundation for many years of TroubleFreePoolCare (when you aren't in the pool enjoying it first hand!)

 

[timerguy]

If I've read correctly, t-15 Cells come in a variety of capabilities/ratings. Are you sure yours is rated to be at least 150% of your pools capacity?
Where are you getting your bleach? I don't believe I've ever seen 7.25% If you're getting it from a dollar store, you may be buying it very old and greatly depleted strength. I get any bleach I use from Walmart since I know they go though their inventory quickly with new shipments arriving 2 or more times/week. We don't insist or require anything. We do ask for your help in helping you. That is done by your reading, reading, and more reading , and taking in/understanding the method we recommend for keeping a "Trouble Free Pool". You've already got one of the "recommended" test kits. Please post your pools details in your signature. And keep asking questions.

 

[jblizzle]

All T15 cells are rated to 40k pools and the output of 1.4 pounds that was listed above. It seems to be quite undersized.

 

[timerguy]

Guess I didn't read correctly. But, yes that's what I was getting at. The swg is inadequate for his pools capacity.

 

[wgj10]

We have a Hayward goldline turbocell 15. I believe its rated for 40,000 gallon pools. I'll take a picture of the exact product info when I get home. When I say 44k gallons for our pool, it is an estimate based on our size (56x22, roman style, 9.5 deepest, 40 inch shallow, about 5 foot in the middle, with a 10 foot spa), and the observed measureable impact of adding chemicals. I'll update the exact specs of the pool for my signature when I get home too. I wouldn't be shocked if the PB put in something that wasn't enough for our pool. Is there an SWG that would be more applicable?

 

[jblizzle]

A second AquaRite with T-15 would work. Or there are a couple brands that make SWGs with higher outputs (I am not sure which off hand).

 

[RobbieH]

My pool is the same size as yours. It takes a big SWG to keep these pools chlorinated.

One thing I notice right off the bat is that your CYA is far too low.

My recommendation: Add CYA to bring it up to 70-80, add bleach to bring FC to 6, and increase SWG output as described above to maintain a target of 6-7 FC.

 

[wgj10]

So If I understand all this correctly, even if I'm off and my pool is 40k, and I increased CYA and stabilize other chemicals, I would basically need to run my t-15 and filter pump almost 24 hours (which I assume for the longevity of the equipment and the health of my electric bill is not ideal) to maintain a healthy min chlorine level. Is that about right?

 

[timerguy]

That sounds about right. That's why everyone suggests a swg rated at least 1.5 times the pools capacity.

 

[RobbieH]

Mine is rated for 60,000 gallons and has to run 22 hours at 80%. In fact, I may even have to turn that up because of the really high heat we are experiencing here at the moment. Going to test the water later today and see where I'm at.

Do you have a two speed or variable speed pump? If so, you can do like I do and run the pump on low (or in my case as low as I can without stopping the SWG).

 

[wgj10]

I don't think ours has multiple speeds. But I'll check tonight. Thank you. Related question, if I paid to have a 60k rated cell put in (non Hayward I suppose), would I need to change my pro logic goldline control box too? Is it easier to add another aquarite t-15 for that reason (no idea what that would cost, need to look into it).

 

[jblizzle]

The Prologic will not control another brand SWG directly, but it could through a relay I think. It is designed to work with another AquaRite and cell though ... You would need the cell and the control box which would be linked to the Prologic.