Why Can't I Clear My Green/Blue Pool Water?
It started very green a month ago and after shocking it several times and putting clarifier in 3 times it is still not completely clear. I can see the bottom and it is in between blue and green with dust on the bottom. I have a cartridge filter and a Ray Vac pool cleaner. I have cleaned the filter several times. The chemicals are: Chlorine 10ppm pH 7.4 Alkalinity 80 Hardness normal range Cyanuric acid 100 Help! Thanks for your question First you always need to be sure you're hitting the shock point. Whenever I shock a pool I always go for a little extra, maybe 12 - 15ppm. It's better to go a little higher than lower. All of your chemical ranges seem to be fine. It's the cyanuric acid (CYA) I'd like to touch on. It seems like your CYA is a bit high for your chlorine level. Your CYA should run 7.5% of your chlorine level. Your level is 100 and your chlorine level is 10ppm. At 7.5% of your 10ppm chlorine, your CYA should be 75ppm. The CYA needs to increase as your chlorine level increases, and vice versa. With a level of 100ppm, your chlorine should be 13ppm, which is a good shock. Now, the only way to reduce the CYA is to drain 1/3 - 1/2 of the water, refill, and balance the chemicals. I wouldn't suggest this right now because of the algae issue. Manually dose your pool daily with chlorine to keep the level between 13 - 15ppm. This will be more in line with the CYA reading you have now. Clean the cartridges every day. You can also get another set and swap them out with the old ones. The next day clean them and swap them out. By doing this you'll reduce any down time. Watch the clarifiers because adding too much can actually backfire on you and cause more problems in a short period of time. Your pH and alkalinity are fine. Be sure to use liquid chlorine as granular will increase the pH level and you don't want that. Chlorine works better at pH levels below 8.0ppm. Really, the only way to clear up an algae problem is to shock, filter, backwash, brush, vacuum, test, and make chemical adjustments. One of the main things people do is to allow their chlorine to get below 10ppm while clearing their pools. Again, remember to manually dose your pool and keep the chlorine level up above 10ppm while you're going through this. Here are some good questions that I've answered about clearing up green pools: How To Clear Up A Green Pool In Woburn Problem With Swimming Pool Green Algea MY POOL ISN'T WORKING PROPERLY..CLOUDY/GREEN WATER There are links to the pages about chlorine, shock levels, and how to clear green pools. And lots of information on the Q&A page about green pools and algae: Swimming Pool Questions and Answers Thanks again for giving me your chemical readings. It makes my job much easier when I know what they are. Good luck with your pool. Robert |
