Why Did My Pool Turn Green This Winter?

If you’re opening your pool expecting crystal clear, summer ready water, you might be surprised when the cover comes off.  At this point, you might be thinking, where did I go wrong? There are a few reasons why this may have happened. 

1. The Way You Close Your Pool is the Way You Open It! If you have leaves or algae in your pool when you close it, those things aren’t going anywhere. If you have your pool professionally cleaned, or clean it thoroughly yourself before your pool closing, you have the best chance to open your pool to cleaner and clear water.

2. You Didn’t Have Your Pool Professionally Winterized. This is the biggest cause of green water. When you hire a professional, they make sure they are taking the proper steps to close your pool. They are checking your water chemistry and they are making sure there is adequate sanitizer to keep your pool blue all winter long. It is important to make sure that your pool water is balanced, and that the perfect amount of shock and algaecide is applied to the water to prepare your pool for the winter! It all boils down to the way your pool looks at the closing to ensure the best outcome when opening it the following season. Y.E.S offers cleanings prior to your pool closing, so your pool has the best chance of opening blue. Now, there are other factors that turn your pool water green, that even a professional closing can’t prevent.

3. Your Cover is Too Old or Damaged. If you had your pool professionally winterized, and your pool has turned green throughout the winter, this may be a signal that it’s time for a new cover. Pool covers can get less effective throughout years of sun exposure and general wear and tear. If the cover is damaged or warn, it \ allows UV rays to penetrate the water. Chlorine breaks down in the presence of UV light, so the more sun exposure your pool has, the less chlorine remains in the water. Additionally, a cover with any tears or even pinholes in it may allow rain, snowmelt, and other contaminants from entering the pool, compromising the water chemistry.

4. You Have a Mesh Cover or Drain Panels. A solid safety cover is the best way to keep your pool clean and clear all winter long. These covers keep out harmful UV rays, winter air pollution, and block the rain and snow, maintaining water chemistry all winter long. A mesh cover does not block as much sun as a solid cover and it allows all the water and snowmelt to enter the pool, which makes it almost impossible to keep clear blue water over the winter. Similarly, a solid cover with drain panels allows microscopic contaminants into the pool throughout the winter, consuming the chemicals and enabling the water to turn green. Mesh covers are still a great option, and remove the arduous task of pumping water off your cover; however they are not ideal for maintaining water chemistry throughout the winter.

5. It Was a Warm Winter. If you live in New Jersey, you are no stranger to the unpredictable winters that we have. It has stayed warm well into October, with frequent large fluctuations in temperature. When the weather outside is above 50 degrees, the pool is at risk for being an algae breeding ground. Winterizing chemicals do a great job of warding off this growth; however this consumes the chemicals leaving your pool vulnerable.

So, your pool didn’t open crystal clear this year. It’s okay! You can take some preventative steps at your next pool closing, and call Y.E.S. Contractors to get the job done right.