Question regarding CYA and rain storms.

[rodog123]

Hello I have a new pool (2weeks old) and am using an inline chlorinator "pucks" I know many peeps prefer the BBB method.

I have yet to test for CYA as I'm using the free taylor kit that my PB provided me for free, its a basic kit does not include cya. I will buy a TFT kit as soon as this one runs out.

1. My question is when rain storms hit and replaces some of the water in the pool I would expect my CYA to go down correct? I live in Houston and we have some crazy rain storms, street flooding is a regular occurance here in this part of Texas.

2. How long after using pucks and shock should I expect my CYA to rise causing my chlorine to become less efective? months, weeks, years?

 

[zea3]

If you go to the poolmath tab at the top of this page, at the bottom of poolmath is a section called Effects of Adding Chemicals. A typical chlorine tablet is about 8 ounces of trichlor. Enter the information for your pool on the colored table then go down to Effects of adding chemicals and see how much a single trichlor tablet raises CYA in your pool.

 

[pragmatic]

As zea3 mentioned, a direct calculation will give you a guideline but no substitute for regular testing. For example; I completely stopped using my in-line chlorinator end of last summer. Winter and spring were not a problem; easily maintained FC with clorox & pH with MA. With an occasional CYA check, I thought I was "The Master". However, I underestimated the affect of our recent rains and apparently the increase swim-load (splash-out). CYA dropped from 75 to <30 in about 4-weeks. I'm now setting my in-line (Pentair Model 320) to 1-1/2 and will give the CYA a check during the rainy weather weeks.

 

[rodog123]

If you go to the poolmath tab at the top of this page, at the bottom of poolmath is a section called Effects of Adding Chemicals. A typical chlorine tablet is about 8 ounces of trichlor. Enter the information for your pool on the colored table then go down to Effects of adding chemicals and see how much a single trichlor tablet raises CYA in your pool.

Thanks zea3 for the response. So going back to my first question if rain water enters pool will my CYA go down?

 

[duraleigh]

if rain water enters pool will my CYA go down?

Not really. Evaporation increases the concentration, rainfall returns the concentration to normal.

 

[Divin Dave]

I live in Texas too so I know all too well about the Texas floods we have.

In additon to what duraleigh said..... If you have a built in overflow that sends water out of the pool, or if your pool overflows in a downpour, which is entirely possible in a short amount of time where we live, then you will loose some amount of CYA due to the water flowing out of the pool. How much is entirely dependent on factors we really cannot measure. The only way to know is to test for CYA.

Thanks zea3 for the response. So going back to my first question if rain water enters pool will my CYA go down?

 

[jblizzle]

Some members partially drain the pool before storms and divert the roof rain water into the pool to lower the CYA and the CH.