My last mystery Ta ph

[Rogue959]

So I can not for the life of me figure why like clockwork TA sits nicely for 2 weeks at a time about 60-70 then when ph hits 7.9 i drop to 7.6 then TA measures 90?? Then ph rises maybe 4 days back to 7.9 then add acid back to 7.6 . Then it sits nicely again for two weeks.
had pool for 8 months and it is been trouble free apart from the 1500ppm calcium when I bought the house

fc 9
cc 0
ta 90
ph 7.7
Ch 400
cya 80
salt 4300
bor 50
temp 29c

 

[Jezza]

Are you topping up the pool regularly with water containing TA?

 

[ctrav]

Testing your fill water may provide the answer...

 

[Rogue959]

Are you topping up the pool regularly with water containing TA?

yeah as per signature

- - - Updated - - -

Testing your fill water may provide the answer...

Yeah it’s in my signature 60

 

[Rogue959]

This is really doing my head in

 

[aussieta]

the ta reagent is very succeptible to static electricity and makes the drop sizes different
wipe the tip with a damp cloth between drops and aim for about one drop per second

 

[Rogue959]

the ta reagent is very succeptible to static electricity and makes the drop sizes different
wipe the tip with a damp cloth between drops and aim for about one drop per second

ok thanks ill give that a go, also is it when the sample goes completely red or on the colour shift as soon as some red shows?

 

[aussieta]

count drops until last drop makes no difference to colour then subtract the last one drop

 

[Rogue959]

count drops until last drop makes no difference to colour then subtract the last one drop

is that the same for calcium and other tests? thanks

 

[aussieta]

is that the same for calcium and other tests? thanks

calcium and ta , fc and cc stop when changes to clear last drop is counted
basically you dont count the last drop if it made no difference
exception is salt test k-1766. stop when first change from yellow to salmon pink

 

[AUSpool]

This is really doing my head in

I think maybe your just trying too hard. Your numbers and the time line in the opening post sort of coincide with what I’d expect. Over time with warm water and 60ppm TA in your top up water your TA will slowly rise. Adding acid will reduce it a little each time.

 

[AUSpool]

Geday Rogue,

Ive been thinking a little more about this and think your answer is within the precision of the test which is +/- 1 drop below 10drops and then +/- 10% above 10 drops. Don’t think too much of this, all tests have a range for precision - the drop tests are quite robust. Applying the given precision to your first test at 60-70ppm, I’ll call it 70ppm, the actual TA level could be anywhere between 60 - 80ppm. I guess you were probably on the low side but your TA was slowly increasing until you recorded the 90ppm test. Applying the precision the actual TA level could be anywhere between 80 - 100ppm. I guess you were on the low side but still just enough to get 90ppm and you probably only just skipped an 80ppm reading.

But as I said before, don’t read to much into it. Your levels look good to me and your obviously all over it, sit back, relax and enjoy your pool.

Edit: Generally you numbers are good but you could reduce your FC a little and work on reducing your TA a bit too.