I have been visiting this forum for a couple of months anticipating my becoming a pool owner, which happened Friday when we moved into a 10yr old house with a pool that was built during construction.
Please note this is an INDOOR pool, approx 15000 gallons. I became suspicious when I found some stabilized chlorine in the storage area.
So before unpacking, I took out the ColorQ that I had ordered and here is what I got at a pool temperature of 62 degrees:
FCl - 0.07
TCl - 0.28
pH - 7.6
Alk - 106
CH - 220
CYA - 96!!!!
I then decided to heat up the pool and retest the next day. The ColorQ manual says that CYA can read high at low temperatures, so here it is at 78 degrees:
FCl - unreadable
TCl - 0.12
pH - 7.4
Alk - 102
CH - 199
CYA - 111!!!!
I diluted the pool water with tap water by 50% and retested the CYA, and it came out to 56.
Please note the water looks clear, no visible algae, there is no smell of chloramines, and the vinyl liner was replaced 3 years ago. There a a few small windows in the pool room, but the pool does not really get any sunlight through them.
Right now it will just be me and my wife swimming, i.e. no pool parties. The previous owners were using a pool company to maintain the pool. Ideally I would drain the pool and refill to get rid of the CYA, but then I would have to replace the vinyl liner. Repeated partial draining and refilling (i.e. 10-25%?? I don't even know how much is safe to drain a vinyl liner pool?) would take a long time and waste a lot of water to get the CYA level down to 20. I know there is a method of using a tarp/plastic sheet to simultaneously drain and refill, but that seems like a big job....
Any advice? Do I need to add more bleach or is that futile with such a high CYA level in an indoor pool? Is it safe to swim in? Is it feasible to run an indoor pool with such a high CYA level? Any help much appreciated.