Where I live in the Pacific northwest, we get about 5 swimming months per year. For the winter though, it rarely goes much below freezing, so we don't close our pool, we just leave it open and stop heating it. Thus far all I've been doing is boosting up the chlorine before the temperatures drop, and then periodically draining it as rain water brings the level up. (We get a lot of rain over the winter.)
Haven't had any noticeable problems, and the water stays clean and clear over the winter; balance it in the spring and everything is good. It's a fiberglass pool, so I assume relatively tolerant of low calcite saturation, but having learned a bit more about that recently, I am wondering if I should be doing more to keep things in balance over the winter.
With the amount of rain we get, it's replacing a good amount of the pool's water over the winter—at the end of the swimming season we're at 3300ppm salt; by the time I'm balancing the next spring, salt tends to be down to ~1600ppm. Naturally, TA and calcium drop similarly.
So, by late winter we could have something like
Temp: 2-8°C
TA: 40
CH: 120
for a CSI of ~ -1.5
Again, I haven't noticed any problems in the 4 years we've had the pool, but that still seems like it could be less than ideal. So, question is: given the amount of water that's being replaced, should I be balancing over the winter? Downsides would be increased effort (going out in near freezing to mess with the pool not my favorite way to spend time!) and chemical use (since much of what I add will be flushed out by added rain water). But obviously worth it if the very low CSI is damaging the fiberglass / piping / etc.
Haven't had any noticeable problems, and the water stays clean and clear over the winter; balance it in the spring and everything is good. It's a fiberglass pool, so I assume relatively tolerant of low calcite saturation, but having learned a bit more about that recently, I am wondering if I should be doing more to keep things in balance over the winter.
With the amount of rain we get, it's replacing a good amount of the pool's water over the winter—at the end of the swimming season we're at 3300ppm salt; by the time I'm balancing the next spring, salt tends to be down to ~1600ppm. Naturally, TA and calcium drop similarly.
So, by late winter we could have something like
Temp: 2-8°C
TA: 40
CH: 120
for a CSI of ~ -1.5
Again, I haven't noticed any problems in the 4 years we've had the pool, but that still seems like it could be less than ideal. So, question is: given the amount of water that's being replaced, should I be balancing over the winter? Downsides would be increased effort (going out in near freezing to mess with the pool not my favorite way to spend time!) and chemical use (since much of what I add will be flushed out by added rain water). But obviously worth it if the very low CSI is damaging the fiberglass / piping / etc.
