Stabilizer keeps increasing???

[lewis]

I have been using non stabilize tablets for almost 2 months and the stabilizer levels keeps rising.
The person at the pool shop says it is not good to swim in anymore unless I drain 1/2 of the water out of the pool.
And he says it will destroy my liner.

Any ideas???

 

[linen]

If they are not stabilized with CYA then the only other tablet type I know of have calcuim in them (cal-hypo). Which tablets do you have? What is your CYA level?

 

[Ohm_Boy]

Can you check the ingredients listed on your container of tablets?
If it says "Trichloroisocyanuric acid" or " 1,3,5-trichloro-...[whatever]..." or some variant of "trichlor", then it is what we call 'trichlor'.
If it says "Dichloroisocyanuric acid" or "1,3-dichloro-[whatever]", or some variant of "dichlor", then it is what we refer to as 'dichlor'.
Both of these are stabilized chlorine sources, and will raise the CYA (stabilizer) level.

If it is "Calcium Hypochlorite" or Cal-Hypo, then it is not stabilized, but does contain calcium and will raise the calcium level.

Both CYA and Calcium additions are pretty much permanent. Once added, they do not generally come back out, and the only way to reduce the levels are to drain some of the water and replace with fresh, or in some areas, a reverse-osmosis treatment may be available and cost-effective. I believe that in North Carolina, water is cheap, and you should just drain and refill.

You do not have to drain all of the required amount at one time though, and there are a couple of tricks to help avoid wrecking the liner. One would be to do a series of partial drain/refill cycles, which would reduce the CYA amount a little bit each time, but will not expose too much of the liner. The other is to try to drain and replace at the same time. Pumping from the top while filling into the bottom will also work, as the colder fill water will tend to stay low.

One last thing - most CYA tests have a high measurement limit at 100 (Some may be different, like 120). Anything above this will test as 100, and one cannot readily know how much above 100 the sample may really be. It may be 150, it may be 200, it may be 500. It may be a bonzillion, but in reality, that is pretty rare.
Still, depending upon the actual levels, you may drain and fill 50% and still have a high CYA level. Just so you know.

 

[uhwelliuh]

I'm recently having the same problem. Thought it odd as I haven't added any conditioner this season. I was using only tabs for most of the summer and CYA levels were normal. Then I shocked it a couple of times with Power Powder Plus (PPP)shock from Leslies and that is when the CYA level shot up. Asked Leslies staff and was told that the PPP has no conditioner but that the tabs do contain conditioner. The label on the tabs says that it is 99% "trichloro-s-triazinetrione" so according to the last post Leslies was correct about the tabs containing conditioner. The label on the Powder Powder Plus lists the active ingredient as "calcium hypochlorite" and that is 73% of what is in the bag. The label is silent as to what makes up the other 27% of the contents but does say that portion is inative. I would think that if the PPP did contain stabilizer it would be listed as an active ingredient, but it makes me wonder what makes up almost a third of the product I have been adding to my water. Anyone know? Also, can anyone recommend chlorine in tabs and in shock that definitely WILL NOT increase CYA?

 

[Ohm_Boy]

All chlorine products add something to the water in addition to the chlorine itself.
Trichlor adds 6 ppm CYA for every 10 ppm of chlorine.
Dichlor adds 9 ppm CYA for every 10 ppm of chlorine.
Naturally, both of these will elevate CYA pretty quickly, especially dichlor.
Calcium Hypochlorite is about 1/3 calcium, so it will raise the calcium levels. It should not affect the CYA levels. As to the 27% of 'other' ingredients in the Leslies product, all I know is that it is inert, and for most purposes can be ignored.
Sodium Hypochlorite will add some salt to water in addition to chlorine, but the levels are pretty small and has never been found, to my knowledge, to be a measurable problem in any pool, as virtually any splashout or rain will counter it.
Lithium Hypochlorite may add some metals, notably lithium, but it's so expensive that I don't know anyone that uses it. Or could afford to use it for long. It may be the perfect sanitizer, or it may be cheaper to treat the water with weapons-grade plutonium, for all I know. You're on your own with this one.

So... why all the different products?
The tabs are really convenient. They can be placed in an erosion feeder and left to do their thing. They are are easy to handle, easily stored, and have a good shelf life.
Powders are easily broadcast, and pack a lot of "chlorine power!!", are easily stored and have a good shelf life.
Liquids are more cumbersome to store and handle, and are more sensitive to loss of efficacy from sun/heat/time.

As you can see, there are trade-offs with everything. For us, sodium hypochlorite (liquid chlorine, or bleach) is the simplest and best product with the least side effects of all of the available chlorine sanitizing products. Can the others be used? Certainly, if one knows about and is prepared to deal with the additional effects, such as drain/refill for trichlor/dichlor/cal-hypo, and the ultimate bank account vacuuming that comes with lithium.

uhwelliuh - not sure what to tell you about your CYA levels and the calhypo. My first instinct is to suspect the testing. CYA tests are, at best, plus/minus 10, and testing variations of time, light, reagent age, procedure consistency, as well as the person doing the testing can all impact the result. Variations of 50 or more between the same test performed at different pool stores are common.

 

[lewis]

Thanks for the replies. The tabs I have been using are Calcium Hypochlorite 68%, so they are the non-stabilizer kind. Do I understand correctly that liquid (household) bleach has no stabilizer? I would like to be able to use this but I have no idea how much to use or how often to use it. It's somewhere around 18-20 thousand gallons with a vinyl liner.

 

[x2rider]

That is correct, chlorine bleach contains no stabilizer.

As for how much to use, www.poolcalculator.com

Go to bottom, select trouble free pool, whether you have vinyl liner, etc, calculate your pool volume, and put your measured values in the left column and select what size/potency of the bleach you have. Hover over the text box and it will tell you how much to put in.

 

[linen]

Good advice above.

CYA: if you are not adding it, it will not increase (unless you have evaporation AND DO NOT replace the water/bring your level back up...this is not a likely scenario except after closing). How are you testing for CYA? Please post some recent numbers.

What is your CH level? As mentioned above continued use of cal-hypo will raise CH. What pool surface do you have? Better yet, please put your pool/equipment details in your signature. Even vinyl pools can have too high CH.