Low Alkalinity and pH levels..Still Have A Green Pool..
by Todd
The pool was dark green. I shocked it 4 days ago, but there is still alot of algae on the bottom and the water is very cloudy (cannot see the bottom). I tested the water with a test strip, and it showed that the pH level was very low, the FC was 0 and the alkalinity was low. All three categories were at the lowest color. What should I do? Thanks for the question Todd You're on the right track in shocking the pool. That's the only way to kill pool algae and get rid of it. After a good shock the water should start to turn a grayish/white color. This means the algae is dying out. If this has not happened you'll need to shock it again. Swimming Pool Algae Green Pool Water The reason the chlorine level is showing zero is the algae has consumed all of the chlorine. The question doesn't say what kind of pool filter you have, but whatever it is, it's very important to keep it cleaned out. Either backwash with a sand or DE filter once per day or when the pressure gets 8 - 10Psi over your "just backwashed" pressure, or keep the cartridge filters changed out. Be sure, if you can, to scoop out any debris from the pool; grass, leaves, etc... You want all the chlorine to go to the algae and nothing else. Use a large leaf rake, not a blue square skimmer. Get a broom and scrub along the water line to break up any debris. I would encourage you to get a Taylor FAS-DPD K-2006 pool test kit. It's the best on the market. Water Testing Kit Pool Water Testing Be sure you're hitting break-point chlorination. This is when you bring the chlorine level up 10Xs what is normally run. Without this the pool algae will just sit there. Here are some links for charts you can use: Pool Shock Swimming Pool Chlorine You'll need to use sodium bicarbonate to raise the pH and alkalinity levels. There are products like soda ash to raise the pH but not the alkalinity too much. Also 20 Mule Team Borax for the pH does the same thing. If the pH is a little low, don't sweat it too much right now. Chlorine actually works better at a slightly lower pH. Once the algae is gone, it will be time to adjust the alkalinity. Add your bicarb in the deep end with the pump off. Allow it to sit for a few hours, then turn the pump back on. You'll need to wait for one complete turnover of the water before you retest. This is usually about 10 - 12 hours. Pool Alkalinity Total Alkalinity Make another adjustment if needed using the same technique. Raising the pH is just the opposite. Make a slurry with the bicarb or soda ash and broadcast it around the perimeter of the pool with the pump on. Allow for a complete turnover of the pool water, then retest and make another adjustment if needed. If you have any water features such as slides, waterfalls, etc... now would be a good time to turn them on. This will help increase the pH level without much happening to the alkalinity. Swimming Pool pH Levels Pool pH..Balance & Adjust You can also go through questions that I've answered in the pool Q&A forum. There's lots of great information and hundreds of questions have been answered. Swimming Pool Questions and Answers Remember, this will take patience. Just keep at it and you will have a great pool this Summer. Good luck and let me know the results. Robert |
