Whats your FC loss with your pool covers?

[gsxr1181]

For those who have a pool cover, I'm curious what your FC loss per day is?

I've put a clear pool cover over my pool, mainly to prevent evaporation and FC loss. But I still have quite a bit of FC loss per day.

Before I installed the pool cover, I was loosing 4 ppm of FC every day. Now with the cover installed, I'm losing 3 ppm of FC every day. I was hoping for better results then that.

I know nothing is eating up the chlorine, as I've done an overnight hold test, and only dropped .5 ppm.

Here is my complete test results.

FC 6 (Before adding bleach. I try to keep between 8-10 ppm)
CC 0
PH 7.5
TA 75
CH 150
CYA 45
TEMP 92.5F

 

[frustratedpoolmom]

I just got a new cover in June, dark blue/black. The first two days the cover was on 24/7 and I lost 0 FC. I was stunned. I went on vacation for 10 days, shocked the night before I left to 16 came home and FC was 8...

 

[gsxr1181]

I just got a new cover in June, dark blue/black. The first two days the cover was on 24/7 and I lost 0 FC. I was stunned. I went on vacation for 10 days, shocked the night before I left to 16 came home and FC was 8...

Interesting, I'm wondering if mine being clear is allowing more UV to get into the pool, burning off the FC?

 

[orthofish]

I had asked that question some time back about the clear cover allowing sun to still eat up chlorine. Seems you have answered it.

 

[chem geek]

My electric safety cover is mostly opaque (tan) and I lose about 1 ppm FC per day with 1-2 hour per day pool use, but even without use the loss is around 0.8 ppm FC per day or thereabouts. The pool is usually at higher temps at 86-90F.

It would seem that the clear cover isn't blocking UV very much. That's disappointing since one wants the light to come through for heating, but wants to block the UV to lower the chlorine usage.

 

[gsxr1181]

Well guess this confirms that if you want low FC loss, go with a colored cover.

If you want hot water, go for the clear. Mine hit 94 degrees today! A little to warm for me. I've pulled it off to cool it down a little.

Wish I would have know this, as I would rather have the low FC loss over boiling water.

Lesson's that we learn