I think I want to go salt.

[estermer]

Here are my test results.

Free Chlorine 3.0
Total Chlorine 3.0
PH 7.6
TA 110
Calcium Hardness 270
CYA 30
Total Disolved Solids 650

[Poolsean]

Looks like a case of low cyanuric acid ??!!? Tri-chlor tabs being used and low cyanuric acid? Very Interesting!
Any chance your pool having an Automatic Water Level device and perhaps a leak somewhere?

If not, it's possible that your low cyanuric acid is allow the sun's uv rays to degradate the chlorine.
You can use a Salt Chlorine Generator, but as with very wise recommendations, you're better off upsizing the cell to the largest one you can afford. This should provide a higher chlorine output, longer warranty, and longer cell life.

[SJohnson]

If there's a leak or constant refilling, wouldn't his total dissolved solids be lower??, 650 seems a little high to me . . . I say bring your CYA up to at least 60 before you install the SWC. Triclor use with low CYA levels, hmmm . . . something's not right with this picture, I agree . . . All those numbers look exactly where you want them to be!!

You're not using Calcium Hypochlorite are you?? You did say, "I regularly dump about 1 pound of granules" . . . That would explain allot, but I didn't think you were supposed to use that with in-line feeders . . .

SJohnson

[estermer]

Well the water in the pool has only been in it for about 10 months. I have also backflushed my filter twice since then and had to drain off some after a heavy rain.

The granules I put in is Sodium Dichloro-s-triazinetraine dihydrate and I put it directly into the pool.

What is the optimum level for CYA for a bleach pool and for a Salt pool?

[SJohnson]

Is that the same as sodium dichloroisocyanuric acid?? Anyway, the accepted levels for a "bleach" pool are around 30-50 ppm. Where the Salt Cell manufacturers recommend 60-80 ppm, I believe. Again, some on this site keep their levels much higher, say 120 ppm, with very high levels of chlorine to offset the conversion of chlorine to chlorimide, or chlorine lock, where the chlorine no longer is actively disinfecting the pool water. PoolDoc(Ben) wrote somewhere that high levels of CYA could be considered a good thing, where it preserves your chlorine longer and prevents it from being burned off in the sun. This way you don't have to add chlorine as often . . . it had something to do with the chlorine's reaction time to bio-bugs in the water. The downside being that highly stabilized chlorine has a slower reaction time than chlorine with lower levels of stabilizer in the water. I think he said high stabilizer levels kept the chlorine in reserve and released it as needed, but the time it took to release the chlorine added to the chlorine's disinfection reaction time . . .Something like that, I remember the article or thread was a very interesting read, wish I could track it down, but it may have been lost when the board crashed . . .

Hope this is helping you, I think you just need to bump up your cya levels a little . . . the debate is ongoing about cya levels and where they should be, everyone seems to differ on that subject a little.

-SJohnson

[SJohnson]

Wait a minute . . . You said that you have an inline chlorinator and you add granules every few days? You put trichlor tabs in the feeder and are dumping dichlor granules in the pool directly? Is that right? CYA levels are usually very stable so minimal draining and backwashing will not lower it all that much. Hmmm. Did you test the CYA or did a pool store test it? That kind of Dichlor your using is 56% chlorine whereas Trichlor is 90%. 1 lb of Dichlor should raise your chlorine level about 3 ppm, in summer heat, direct sun, every 3-4 days, that doesn't sound all that unreasonable . . . you're gonna love the Salt Cell . . . I'll bet.

SJohnson

[Poolsean]

SJohnson, 650 ppm TDS is not too bad. Most tap water is really low, about 100 ppm. I would say that 10 months of tri-chlor and di-chlor, both of which adds salt and cyanuric acid to the pool, would have increased the cya level and salt level higher. The backwashing and rain water drain off, would account to a lower level, but a leak would certainly lower these levels much more than normal.
However, since there was no response about an automatic water fill line, or any suspicions of a leak, there probably isn't one. OK...so back to what is consuming your chlorine at a higher pace than normal. One should not need to have a tri-chlorine erosion feeder AND have to hand dose di-chlor.

Have you added anything other than chlorine and acid to your pool? Take that back, since tabs and di-chlor are both low on the pH scale, no need for acid, but perhaps some soda ash, to increase pH. Any algaecides, clarifiers, or additives? If so, these may be reacting with the chlorine added and just plain and simply, using up the chlorine.

[estermer]

The only chemicals that have ever been in my pool in addition to the two forms of chlorine already mentioned are Acid, borax, and bleach. After the initial acid washing and needing to raise the PH, chlorine and acid are the only things I need in my pool. My PH creeps up and I usually need about 1/4 to 1/2 gallon of acid per month to keep it at 7.6.

As for an automatic water line, yes I have one. Although it is possible that I have a leak, I really doubt it. We had some heavy rain last week and it filled the pool up. A week later, it's still very full and I know the auto fill hasn't kicked in. When I first had the pool remodeled last year, I quickly spotted a leak as the fill line was almost always on and the water level would drop pretty fast.

So I am thinking that I need to up my CYA to at least 50 and then look at the Autopilot 60.

[scoobiedoob]

Our pool is similar in size to yours, maybe 2000 more gallons. We got our Autopilot 60 last year and love it. I can't say it will be the same for everyone because it appears there are a lot of factors, but it has been a breeze to maintain our pool since we got it. The water stayed beautiful all winter long and since we've had it we've added a total of about 2 gallons of acid and maybe a few cups of clarifier just for good measure. All testing has been excellent with the Pool Solutions test kit, which is a fine kit. We just added a 150 lbs of salt for the beginning of the warm season along with a few lbs of CA. I checked our cell the other day and it still looks brand spankin' new. I can't speak highly enough about it... best move we've made for convenience and ease of pool care.

[CarlD]

OK,
I'm a bit confused: Your numbers look EXCELLENT!

I have no idea why anybody worries about TDS--it has little if any effect on your pool--it MIGHT indicate the presence of metals--but they should be tested for separately. You already have a good calcium and total alkalinity number.

I have no idea why PoolSean thinks your CYA is low at 30ppm. I might consider going to 40 or 50 ppm given your conditions, but I do not like going higher. Your FC is FINE for 30ppm

The only baffling thing is if you are using tri-chlor tabs in a feeder and di-chlor powder to supplement, why is CYA only 30? This has been picked up by the other posters.

There are only two possibilities (also noted by others):
1) You have a leak and are re-filling all the time such as by an auto-leveler (they sound so complicated but they work just like a bathroom toilet's float valve--that simple)
2) Your pool store tested wrong. Could they really do that?????? Well, yes. You can get more accurate numbers from the $15 WalMart HTH 5-Way test kit (if you can still find them in your area--long gone in mine). And, of course, from Ben's kit or the Taylor kits. I suspect your CYA is much higher.

Someone said Ben recommended higher CYA levels. That's not exactly right. Ben HAS said there is no problem with running higher CYA levels as long as you follow the rules of keeping your FC at the approriate levels, and you might see less see-sawing of FC.

But everyone seems to forget that Ben has also posted another article showing that the advantages of higher CYA levels fall off dramatically once you get much above 25-30ppm--you don't protect chlorine much and you lose effectiveness...So which is true?

So I generally aim for 30, and if like the originally poster, I am in for weeks or months of plus 90 sunny weather (and, yes, we get that in New Jersey--my backyard frequently hits 100 by mid to late May), I may run CYA to 40 or even 50, especially if I seem to use a lot of chlorine.

But you have to be careful--despite doing that last summer I had a minor algae bloom--the first in this pool and the first in years. I hammered it 3x a day with FC levels of 15-20ppm and in 24 hours it was gone, and in 48 I was back to normal. I was annoyed and annoyed with myself...I broke my own rules and paid for it.