Weird water test results at startup this year...

[TedC]

Hi All!

This is my fourth year opening this pool. I've had two great summers thanks to all the advice here.

I just ran all my ( now three year old ) test kits, and it's mostly OK, but with some surprises - at least to me.

Background - 19K vinyl in ground. 3k ppm salt ( for comfort - no swg ) Good water at the end of the season ( BBB method ). Drained below returns and covered from September until last week.

Pool is now full due to snow melt and rain water.

I fired up my DE filter and put in 5 gallons of 10% 'Pool Chlorine' from Walmart three days ago. Water looks really clear - I'm ready to vac and brush.

Today's readings:

FC 6
CC 0 ( yay! )
PH 7.5
TA 50
TH ( CH ) 250 or less than 20 - two different tests.
CYA - Less than 30 ( test limit )

So:

TH ( CH ) on a HTH test strip - color is nice and dark - 250 +
TH with older HTH drops maybe 20.

Are any of these tests close to useful? Maine has hard well water. This pool was filled last year from lake water, and now has been topped up with snow and rain - maybe 30%?

The TH was more like 250 at the end of the year when I closed it. It doesn't disappear in winter, does it?

My TA was lower than I expected - It was around 100 when I closed the pool. Rain water?

My CYA was around 60 at the end of the season last year. I guess it got converted. Back to WM, I guess....

Anything I should be doing outside the usual?

Thanks!

 

[Richard320]

Hi All!

This is my fourth year opening this pool. I've had two great summers thanks to all the advice here.

You're welcome!

I just ran all my ( now three year old ) test kits, and it's mostly OK, but with some surprises - at least to me.

Background - 19K vinyl in ground. 3k ppm salt ( for comfort - no swg ) Good water at the end of the season ( BBB method ). Drained below returns and covered from September until last week.

Pool is now full due to snow melt and rain water.

I fired up my DE filter and put in 5 gallons of 10% 'Pool Chlorine' from Walmart three days ago. Water looks really clear - I'm ready to vac and brush.

Today's readings:

FC 6
CC 0 ( yay! )
PH 7.5
TA 50
TH ( CH ) 250 or less than 20 - two different tests.
CYA - Less than 30 ( test limit )

So:

TH ( CH ) on a HTH test strip - color is nice and dark - 250 +
TH with older HTH drops maybe 20.

Are any of these tests close to useful? Maine has hard well water. This pool was filled last year from lake water, and now has been topped up with snow and rain - maybe 30%?

The TH was more like 250 at the end of the year when I closed it. It doesn't disappear in winter, does it?

It can form scale on the walls. Can you feel down below the old water line? Is it rough?

My TA was lower than I expected - It was around 100 when I closed the pool. Rain water?

Most likely.

My CYA was around 60 at the end of the season last year. I guess it got converted. Back to WM, I guess....

It also degrades about 3-5% per month. I doubt it broke down into ammonia or you wouldn't be holding any FC. I'd work it up slow. IOt could still be 10 or 15 and if you try all at once you might overshoot.

Anything I should be doing outside the usual?

Thanks!

Yes. Treat yourself to a new test kit. Your old kit and test strips are both substandard. 19000 gallons is a grownup pool, you need a grownup test kit.

 

[TedC]

I haven't noticed scale this year or in the past. It got a new liner last spring, but the old liner wasn't crusty.

I use 'The Pool Calculator' web site with TFP goal levels. It puts my max CH at 300, so I wasn't worrying too much. Since 50 is the goal min, I can work it down. FWIW, the pool surround is concrete - not the smooth stuff. Knee ripping, bathing suit shredding stuff. I do pay attention to the CSI, just in case...

I am a bit embarrassed with my WM HTH test kits. I did get the Taylor kit for chlorine right away - that was my splurge.

Thanks again!