So I'm a recent convert, as I've mentioned in a few other threads. I had been using MA for PH, and 3" trichlor tabs with Chlor-Brite for chlorine.

But I've gotten rid of the tabs and switched to liquid chlorine now, so I'm partly 'there'. I'll have to wait for the start of next season to jump on the TF-100 bandwagon, but I will. I use the basic Leslies DPD kit (FC and PH) for now.

Leslie's water tests have always shown me as having very high CYA (99 -- which is understandable due to all the trichlor -- I get that)... but it also has me as a fairly high 120 for TA. It's always been up there, for the last 1.5 seasons.

Any guesses as to why TA would be that high? Before finding this site, I didn't realize that water aeration caused PH to rise, and had the pool's waterfall on constantly, and thus was always adding MA to lower the PH levels. I've never had to raise PH since I've been here... its been constant MA additions and backwashes/refills/more MA.

Does Trichlor/Dichlor mess with TA? Just seems weird that it'd be that high, with all the acid I've been putting in over the last year. Basically, I've done everything pool school says to lower TA (without knowing I was doing it). But my test results have been steadily high.

I plan to dilute the pool water 50% and see if I get more manageable readings (since learning here that being that high tends to lead to less accurate results).

Oh -- and I know pool store testing is no substitute for a real kit... but they've been consistently the same for sooooo long. It's just weird.

Scary thing is -- I just drained about 20% of the pool the other night, refilled... brought to Leslies -- and my results as far as CYA and TA were the SAME as before the drain-refill.... so they must be off-the-charts bad if Leslie's is to be believed.

Have you ever had them test your fill water?

I haven't done that --- you think the TA could be that high in the fill water? Or you mean just to see if they're full of... well...

If you have "hard" water - white scale on showerheads and clogging your coffeemaker - there's a very good chance the tap water is in the neighborhood of 200 TA. I know when I add water, I can figure a cup of acid for every inch of water I add, just to keep things close. After a day of mixing, it usually needs some fine-tuning.

100 is the highest that many CYA tests are capable of measuring, and everything over that reads as 100. Leslies testing could suffer from the same issue, and thus your CYA could be 99, or 199, or 399. Or a gazillion. OK, maybe not a gazillion. But still, if it is off the scale like that, you may find yourself reducing it and still not be able to measure it. I think that another drain/fill, as you mention, is probably a good idea.

We've seen some pretty high TA in fill water before, too. If you could get a TA test run on a sample of the fill water, it might tell you something.

Thanks for the info guys, I'll bring in some fill water and see what they come up with.

Richard, that would make sense, cause I do get the white build-up on shower-heads. I try to clean out the coffee maker with vinegar fairly often so I haven't noticed that being clogged just yet. Looking like its a good thing I do it.

My fill water has a TA of 325 - 350.

I've just come to terms with the fact that I will probably never have a low TA even with all the MA additions I do since I am adding more TA every time I add water to the pool. Saying that, though, I do seem to be able to keep it around 175 and only add MA once a week or so. My pH tends to linger around 7.6 and when it jumps to 7.8, I dump in some more MA.

Ya, my fill TA tests at 320. This is my first season and I've been working my TA down so I can add borates (for feel). I've knocked it down to 160 after 6 weeks....but with my fill water so high....I'm thinking I may not be able to get it down to my goal. At least not during the swim months.

Am I wrong to think that in the off season it should be easier to bring my TA down?

My only hope for really lowering it would be with the help of rain water. We haven't had any rain here in months.

If you are in an area receiving rainfall, you probably won't have to use as much fill water. You might be able to rig up some rain barrels or a way to direct any run off into your pool. I think rainfall has a very low TA, maybe 10ppm, so you can see how the addition of it instead of high TA fill water, would really help.

My fill water has 220 TA. Since we are experiencing one of the longest droughts of the century I have been adding fill water several times per week. I have worked all summer to reduce my TA.

I forgot to have my fill water tested... Been crazy tiring to get my pool light wired correctly.

But I did dilute my pool water by 50% and had that tested at Leslie's for CYA --- still 99 (AKA off the chart). This is after emptying-refilling about 20% of my pool, and THEN diluted that by 50%.

Guess I'll have to wait till after I have the pool resurfaced to get that CYA level down. The good news is, the water is still crystal clear. Hopefully I can keep it going thru the rest of this swim season.

You have got to get yourself a test kit
I wouldn't wait till next year, it pays back quick!