Do any chemicals "settle" in uncirculated water?

[pinguy]

I just took a water sample from our closed pool to calculate how much salt/CYA I would need for opening. We had a lot of precipitation in eastern PA this winter (water is up to coping), so I was expecting a good amount of dilution. However, the CH drop was more significant that I would have thought. It was at 475ppm at closing, and was at 75ppm from the sample I took. Pool math says I would have needed to replace 85% to see a 400ppm decrease.

Do any chemicals like CH "settle" to the deeper water of an uncirculated pool? Are any of the tests not accurate in cold water?

 

[kcindc]

I don't have any specific scientific knowledge, but the general consensus is that the water needs to circulate for 30 minutes before you take a sample. It is possible that the melted snow/rain water is sitting on top... I'm sure it is compounded with any freezing/thawing action happening during the winter.

I would expect you to see a slight drop in CH if you lowered your water at closing, but nothing close to those results.

Did you store your testing reagents inside and way from the sun?

 

[Richard320]

If the pump isn't working, then yes, you have stratification. It's not unlike pouring a layered cocktail

Stir up one of those drinks and you'll have some shade of brown...


Get the pump running and brush the perimeter of the pool before you test again.

The CYA test is sensitive to temperature. Leave the sample water inside on a sunny windowsill and get it above 70F before you measure it out and start mixing.

 

[jblizzle]

Agreed, you need to circulate before testing because the new water could certainly be sitting on top.

 

[duraleigh]

Great Graphics, R320!

 

[pinguy]

If the pump isn't working, then yes, you have stratification. It's not unlike pouring a layered cocktail

Stir up one of those drinks and you'll have some shade of brown...


Get the pump running and brush the perimeter of the pool before you test again.

The CYA test is sensitive to temperature. Leave the sample water inside on a sunny windowsill and get it above 70F before you measure it out and start mixing.

LOL I was imagining it as more oil and water, but this looks much tastier.

Thanks!

 

[pooldv]

CYA needs to be tested at room-ish temperature.