Swimming Pool Blog - Tips, Care, and Installation

Why Does My Pool Keep Turning Green?

Written by Scott | 7/17/09 9:46 PM

Recurring algae can be a problem for many pool owners and can have several contributing factors.

Some of the main causes of pool algae are:

  • Heat
  • Rain
  • Letting chemicals get out of balance
  • Transferred from one pool to another

Recurring algae is usually Mustard Algae. It is a yellowish green color that usually starts growing on the pool walls and on the pool floor.  It will then turn the pool water green.

How do you get rid of mustard algae (and keep it from coming back)?

  1. First, vacuum the pool on the waste setting.
    Mustard Algae is resistant to the normal chlorine levels so to get rid of Mustard Algae you can use a Yellow Out type product.
  2. To keep the Mustard Algae from returning to your pool, use copper algaecide.
    Copper algaecide should be used as per the manufacturer instructions and should not be used during high levels of chlorine to prevent staining.
  3. Use clarifier to help filter out the algae and Metal Out or Demineralizer to prevent staining.

You'll be back to swimming in crystal clear water in no time!

Tip: One of the most important aspects of keeping any pool clean and clear is to ensure your chemistry parameters are all properly maintained. We recommend keeping these in check with our Safedip 6-in-1 Digital Chemistry reader.

Still concerned about something funky in your swimming pool? Check out these other maintenance related article here (especially the one on REVIVE)!