I received the K-2006C test kit yesterday evening after coming home from work. I tested my pool water right away, and the results did not look good: pH = 8, FC = 25; CC = 0.5, CYA > 200, TA = 250, CH = 380. I added 1 gal of muriatic acid and 182 oz of %6 bleach at 8 PM yesterday. I test again at 7:30 AM this morning, and the results were as followed: pH = 7.4, FC = 27, CC = 0.5. I added another 182 oz bottle of %6 bleach before going to work. My pool water is still deep green, and there are yellow/brown fine dust on the bottom. In the shallower end of the pool, I can tell the wall is slightly greenish/yellowish, but the water is so green in deeper end of the pool that I cannot tell if there is any algae growing on the wall. I've been brushing the pool every 2-3 days and cleaning the filter cartridge every week.

For the last four weeks, I've used about 20 tri-chlor tablets and 12 lbs of di-chlor granules to combat algea growth, and I guess that explains why the CYA level is so high. I have diluted water sample with distilled water (1:1), but the level is still higher than 100. That's why I list CYA level > 200 in the results above. I've also discovered another potential problem with the new tri-chlor pucks that I started to use two weeks ago (I've used about 8 pucks so far). Heeding the advice from this forum, I read the label and find out it contain 2.5% copper. The previous bucket that I just used up only contains tri-chlor. Could copper be the reason why my water is so green?

Here is some background information on my pool. It has an irregular oval shape (like a number 8 with one end smaller and shallower than the other end), with plaster wall. Filtration system consists of a Pentair Clean and Clear 200 (200 sq ft) cartridge filter coupled with a Purex Triton Ultraflow pump. The original pump motor died three years ago, and I replaced it with an Emerson EB841 1HP motor. There is a Nature2 Professional G system installed but I have never replaced the cartridge inside, which is a 35G model rated for pool from 25000-35000 gal. The pool came with the house when I purchased it in 2006, so I do not know the exact volume (I should have asked the previous owner ), but I have always guesstimated it at 20000 gal based on my rough calculation. The Nature2 vessel has developed a crack, which is a source of water leak that lowered the water level too much (below the skimmer intake opening) and caused the pump to stop working while I was on vacation.

I initially used a pool cleaning company to maintain the pool when I first purchased the house. For the past three years, I've been using a local pool store to test my water and add chemicals based on their recommendations. I've been using tri-chlor pucks in a floating chlorinator (2-3 tablets per week during summertime and 1 tablet per week during wintertime), and shocking the pool with di-chlor granules (2 bags per week during summertime, 2 bags once or twice a month during wintertime. I live west of Houston, Texas, so chemical loss is a big problem during the summer, especial this year. About three years ago, the pH level of my pool started to jump up to 8.0-8.4 (from 7.6 for the previous three years). I been adding a gallon of muriatic acid every week (sometimes 2 gallons) since then trying unsuccessfully to bring the pH level down. It seems like a losing battle and I think I've just discovered the reason why. I test my tap water yesterday with the K-2006C kit and the results were shocking to me: pH = 8, FC = 1.6. I've always smelled chlorine from my tap water, but I've never tested it until now.

I'm sorry for the long post, but I think the more information I give the better. I know I have a big mess to clean up and I really need all the help I can get. Your advice is greatly appreciated.

TIA