Swimming pool maintenance may not be your priority.  You may be a new pool owner and haven't been taught the correct way to maintain your pool water.  Perhaps you've slacked off after testing the water repeatedly and no problems were indicated.  Maybe you've even been giving it 100% of your effort and then notice one day green or even blackish coloring in your water.  Regardless of the reasons, it can be frustrating to discover your pool water is green.

Before you panic and drain all the water out, keep the situation in perspective.  Consider it a tough lesson on why you need to stay on top of keeping your pool clean.  After some hard work with the right products, you can get your pool looking inviting again.

Often times a green pool is the sign of an issue with the filtering system.   Remove any debris accumulated in the filtering system.  Does it sound like water is passing through it as it should?  If it seems to be working properly you can move on to cleaning other areas of the pool.  You'll need to let your filter run non-stop for a few days while you're trying to get things turned around.  Make sure you check on it often.  If it doesn't seem to be working properly you will need to get it fixed before you can make any progress.  Replace the filtration cartridge if needed.  Invest in a high quality, reliable pool filter that is appropriate for your pool size.

While you let the filter do its job, move on to cleaning the rest of the pool.  After you're able to see the bottom of the pool, you can vacuum it. You don't want to vacuum prior to that in case there's gunk built up on the bottom which could damage your vacuum and pool.  The solution would be to shock the water to kill algae and bacteria.  This solve the problem and you will begin to see improvement very soon.  

Wait about 24 hours after the shock is complete before adding chlorine or any other chemicals.  Check the pH level with a test kit and add additional chemicals as the results indicate are needed.   Our recent blog post, Is Your Swimming Pool's pH Level Your Priority? can assist you with information on what chemicals would be appropriate.  After roughly 12 hours your water should be clear enough to vacuum any remaining debris.   Visit Swim University for instructions on how to properly vacuum your pool.  This process could take up to 5 days to get your water clear again.

If your water didn't clear up, contact a pool specialist to come to look at your pool.  There may be additional problems that are making your chemicals ineffective.  You may need to upgrade to higher quality.  A pool specialist will be able to take samples and give you additional information on resolving the problem.