Pool Opening Question

[TarheelFan]

First off, I want to thank you all for being such a great resource. My pool season last year was a dream....no outbreaks, in fact, did not even have to shock the pool one time after I got it up and running using the BBB system.

This is my first season that I have opened the pool after using BBB for the prior season, and I just want to be sure that what I am seeing is legit.

I used a dark winter cover and a leaf net to keep the pool relatively clean. There were still some leaves that made it into the pool over the winter, but not that many. When I removed the cover this week, the pool water was clear and I started to scoop up the leaves. I had lost about 20% of the water (I think I have a slow leak somewhere) so I had to add water. Once I finished filling it up and got the pump and filter going, I added about 6 ppm worth of Chlorine and let it sit over night. My goal was to see how much Chlorine I lost to algae. I assumed that I had 0 ppm FC in the pool, but the next morning when I did my first test, it showed 9 ppm FC and 0 ppm CC. Does that seem reasonable? Could chlorine stay in the pool all winter even with some leaves in the pool but with the cover on?

I have read that reagents have a shelf life, so I thought that perhaps my reagants have weakened, but before I order a new bunch, I thought I would see if this is normal or not.

 

[JasonLion]

The water you used to top off the pool probably had chlorine in it, leading to the higher than expected chlorine level.

 

[Bama Rambler]

I tend to believe it's as Jason suspected. That the fill water added the FC. I always test my pool when I open it and usually have at least a trace of FC left after the winter. I use an opaque cover and raise it to shock level just prior to covering it for winter.

 

[Speedo]

Last year I had 8ppm after opening, some of that probably wasn't from the fill water. But the prior year my CYA was so high I closed with just over 30ppm. I should test my water this year before adding any just to see if it's 0, but I will probably forget or be too eager to get things going.

 

[jblizzle]

While the above probably explain it, let me ask:

How old is your kit and how/where do you store it?
I just replaced my TF100 kit that was going on 3 years old (stored in a closet in the house) and all the tests seemed to still be working fine (as compared to the new kit).

 

[TarheelFan]

Kit is about a year old. The Chlorine reagents are 6-7 months old. The rest are still the originals as I only really test PH and FC regularly. It was stored in my garage (my wife moved it out of the house at some point).

 

[jblizzle]

Hard to say if any of the chemicals were affected being in the garage ... what are the temps like in there. Although I think getting a bit cold is not as bad as getting hot or sitting in the sun.

 

[TarheelFan]

I'm in NC. We got down to the mid 20s some this winter, but my garage was shut, so it probably never got below 40 - 45. It definitely never got hot in there, and they are back in the house in my usual spot now that we are prepping the pool to open. For now, I am going to assume that the fill water (I am on city water, so it is treated water) added the chlorine. Thanks again to all for the info.