Just bought my house at the end of last summer, and this is the first pool I've ever had. Fortunately TFP has been keeping me alive in the meantime. It's a 16x30 in-ground, vinyl liner. I'm running a Hawyard 1-HP single speed Superpump and a cartridge filter, with a Pentair inline chlorine feeder. I calculate about 15,000 gallons.
I've been using a $20 poolstore test kit, but I just bought a Taylor K-2006. Some of my problems being that I can't keep the pH above 7, and I've had two major algae blooms this spring already. I suspected the CYA was high, as the previous owner had been feeding trichlor pucks, plus I found a half-empty bucket of stabilizer among the supplies he'd left behind.
The water's been nice and clear for a few weeks now since the last bloom, and we've been swimming daily. My data as of yesterday is:
CH: 440 (we have really hard water here)
CYA: Like I said... through the roof. The highest number the Taylor test kit will read is 100, and it's way higher than that. I'll have to try a dilution to see if I can pin it down closer.
So having been reading here for awhile, I guess I'm fixing to rent a pump and do a partial water change. I've got a 2,500 gallon rainwater storage tank in the garden I can fill up, and the rest will have to go on the grass - I'm on septic, so there's no pool drain to the sewer.
So, wish me luck... I don't see any other way to deal with it. And yeah, I'll have a pool store or someone verify my CYA numbers before I take action. Thanks for all the advice so far. I'll be hanging around!