In October, I took over a pool that was maintained for years by the same pool guy. I only had it for three weeks and did not have the time to wrap my head around the chemistry. I studied up all winter long and I now have a much greater understanding of pool chemistry thanks to this site and its members. We just opened the pool about 10 days ago, and it went pretty smoothly other than a faint green ring around the water line that easily rinsed off, and about a thousand dead worms on the bottom of the pool. I ran the cleaner a few times and subsequently tested the water. These were my results:
PH 8.0+ (pool company later tested and said 8.7)
CYA 300+ (diluted 3:1 tap/pool water, still was off scale)
temp: 46 degrees
I used 1 121oz jug of 8.25% bleach and a 1lb. package of 53% cal-hypo to raise the FC (not at the same time though), and I used dry acid to lower ph. I'm getting muriatic acid soon.
I'm currently doing a simultaneous drain/fill to reduce the CYA, and relying on test strips to gauge CYA levels as to not waste too much reagent during this process. I can only imagine what the CYA level was at closing because I had to drain out tons of snow melt and rainwater-at least 6,000 gallons-and I've replaced another 6,000-9,000 gallons since opening. (PS- I do have a SWG, but I am manually chlorinating the pool with liquid bleach until I can get the CYA level down)
These were my results a few days later
Temp: 55 degrees
The water is crystal clear now, however I noticed that there is a ton of what I suspect to be calcium scaling that I don't remember being there before, although I may not have noticed it. Also, every time I clean the robot, I notice a grayish "sludge" that dries into a very fine white powder. This powder ends up everywhere-if water splashes out and it is allowed to dry, there will be a very pronounced white spot there. When I brush the pool, the water becomes very cloudy and takes an entire day to clear up. A significant amount of this cloudiness occurs when I brush the plaster below the tile line, but above the 'winterized' water line I maintained. My guess is this powder is calcium, but I'm not certain.
My questions are:
1. Is this calcium, and if it is, does it filter out? (I have a DE filter)
2. If the particles are too small to be filtered, how do I remove it from the pool?
3. If it is calcium, will the suspended particles cause problems with my heater? I'm worried that it will cause scale inside the heat exchanger, due to the temp rise.
4. I'm pretty sure the ph was around 7.6 at closing, but what would make the ph rise so much over the winter months? We got so much snow and rain this year, isn't that acidic?