I see so many "green pool" posts, I thought it might help to post a success story. And that story would be mine. For lessons learned scroll to the bottom.
Mid summer last year my pool turned green. And nothing seemed to help. I was making trips to the pool store and pouring algicides into the water. Nothing seemed to help. The pool water was green and I couldn't see the bottom of my 48" deep above ground pool.
The pool store told me about phosphates, so I was anxious to use a phosphate remover. And happily the pool did clear up. I was very pleased. But 3 days later to my dismay the pool was green again, and phosphates still measured 0.
During this time I did discover the trouble free pool website. I starting reading and trying to learn all I could. But I did not heed the #1 rule. And that was the one pertaining to getting a good test kit. I had used test strips for years, and felt pretty comfortable with them. Besides I had poured enough chemicals and money into the pool, why spend more on test kits?
So for the following few weeks I used the pool calculator and raised chlorine to the recommended shock levels. My CA (according the the test strips) was on the high side. So it was requiring levels of 30ppm + to get to the recommended shock levels. Needless to say I was pouring gallons of chlorine in the pool. After 2 weeks I gave up. It was towards the end of the summer and I got frustrated. Out of desperation I drained 75% of the water out and closed it for the season. I would let the fall rains and winter snows fill it back up.
So this spring I started over. I bit the bullet and bought the suggested test kit that is recommended over and over on this site. CA levels were obviously much lower now, and I would find I was now reading it accurately. I then used the pool calculator to determine the recommended shock levels again. I would keep the CA low so that the Chlorine would be more effective at lower levels. I would correct the CA levels after I got the pool cleared up.
I was maintaining Total Chlorine levels, but I noticed that for the first few days that Combined Chlorine levels were up and Free Chlorine down. That told me that something was consuming the chlorine. After about 4-5 days I noticed that the pool was clearing up visually, and the Combined Chlorine levels were dropping to 0. I was maintaining Total Chlorine levels the whole time. This told me that the Chlorine was actually killing something, and was finally winning the battle. After a few more days the pool wasn't green anymore, but was cloudy. It wasn't clear, but I could see the bottom.
I kept monitoring Chlorine and Ph levels, keeping them at their correct levels now. I used a combination of a clarifier and DE to clear up the water. I then also worked on getting the CA up to a 30 ppm level. Within a week the water was clear and the pool beautiful. The only problem now is that the water and outside air temps are a little cold to go swimming yet
So now the water is in balance, and the pool looks great. I am very seriously considering now going the next step with the last "B" and adding Borax to the pool. I like my pool again after about 10 months of green water.
So here are my lessons learned for you with pool problems.
1. Don't believe the test strips. I think my original problems is that my CA was way too high, and I wasn't measuring it correctly. With the CA so high, I was virtually rendering my Chlorine useless. I couldn't get it up to high enough levels to shock with.
2. Get a good test kit. The strips may be ok for quick and rough checks. But a good test kit will be much more accurate.
3. You really can clear up and maintain your pool with inexpensive chemicals.