Background: I bought the house 15 months ago and had a pool guy taking care of the pool. Wife wrecked her car in Dec, had to buy a new one, couldn't afford the pool guy any more, so we took care of it ourselves. Previous pool experience was a 10K gallon salt water pool in FL. This pool has used chlorine tabs in a floater since before we bought it. Had the calcium buildup blasted off the tile in March. I deployed in April. In July wife reports algae that won't come off the wall even with a steel brush (wide). Got home early August. Found a narrow steel brush that got 90% of the algae off (looks like black algae to me). Shocked it. Pool looks nice for awhile. Algae comes back. I found it impossible to maintain chlorine in the water with just the tabs, and end up shocking it every few days. Found this website and ordered the TFT kit. Checked the numbers (below). Now here I am verifying what I think I need to do.
CH: 900ppm (36 drops to turn the water blue-ish. Is this right? Leslie's said 400, but we have hard water here in Tucson)
I put 2 bags of Clorox 20k lb pool shock in the pool 48 hours ago and now I have no chlorine. My understanding is the algae is using it all up, is that right?
Could I really have 900ppm CH or is the test off because the other numbers are off?
CYA: I had to use the dilution method and think this is right. Leslie's said 100, but that's also the top of their 'ok' scale just like the CH was. I live in Tucson with 330 days of sunshine a year so I understand I need more CYA than most folks, but how much is too much? I realize I need to drain some of pool and refill it, but how much? If I drain half of it and refill with city tap water (auto filler on the pool), then I think my end result CYA should be 60 right? Is that good enough?
Thanks for the help, I'm looking forward to getting away from the pool stores. I certainly miss my salt water pool, but I'm not gonna spend $1k on a pool I'll own for another 3 years until the Air Force moves me again.