Is my outside pool an inside pool?

[Kes]

Hi,

I am fortunate enough to have - since mid 2009 - an Abrisud low-profile cover on my pool. We've had the pool for many years in its open state. The cover is a low arc made of an aluminium frame with double-walled polycarbonate sheets. It keeps the dirt out, locks children out, keeps the wind off and heats the water (but is a bu**er to vacuum). It is on permanently, being hinged up on the few very sunny days, and taken off for one day a year to clean. Oh yes, we get into the pool via a sliding hatch which is left open when we swim.

Right. Should I be managing the pool as an indoor pool? In other words with low cya. The FC doesn't seem to drop much at all, but there again we don't have much sun in the UK. At the moment the cya is up around 80 with FC at 5: I'm reducing the cya gradually by backwashing and moving away from trichlor tabs to bleach (and starting a proper test/recording regime). Is the only difference likely to be the cya/FC relationship?

I guess the answer is to test and record and see what happens, but I wondered if there were any other covered outside pool users with experience. Thanks.

 

[ncbrit]

I havent any idea regarding your question, but I did just watch the video of the motorized cover on the aquaflex website. That is cool.

 

[chem geek]

I have a mostly opaque electric safety cover on my pool so the pool is only exposed to sunlight when it is open for about an hour every weekday and longer on weekends. I used to keep around 30 ppm CYA in it and now have around 45 ppm. If your chlorine loss is low, then yes, you can keep a lower CYA, probably around 30 ppm should be fine. I wouldn't go any lower than 20 ppm CYA which is the lowest you can read on the extended CYA test (such as found in the TF-100 -- not sure what you are using).

With 30 ppm CYA, you can have your minimum FC at 2 ppm so add chlorine to get it to 3-4 ppm and then have it drop no lower than 2 ppm. That seems quite reasonable. If for some reason you find that you have trouble keeping Combined Chlorine (CC) low, then you can go for 4 ppm FC with 20 ppm CYA which will give you more oxidiation power to help oxidize bather waste somewhat faster. That would be what could be done in an indoor pool. For you, having decent air circulation will help, at least when the pool is open.