What To Do If Your Pool Water Turns Green (or Red, or Brown…) – Pool Care 101

Quick Dips - What to Do If Your Pool Water Turns Green, or Red, or Brown - Pool Care Guides

Quick Dip: Fixing Your Water Color – Algae, Metals, Etc.


When everything is working as intended, your swimming pool’s water should be crystal clear and have an inviting sparkle. However, algae or high levels of metal in the water can turn that clear blue water into a murky, icky mess. Below are some quick tips on how to deal with this issue.

The First Step

The first thing to do is to determine the color of the water and the source of that color before executing the prescribed treatment. Causes of water color issues can be traced back to the initial fill-water, inadvertent additions of chemicals from water run-off, treatment chemicals that contain copper or other metals and/or poor water chemistry that can cause corrosion of metallic pool components.

Green-Greenish Blue Water

OMNI Multi-Purpose Algaecide 60 - LeisurePoolInc.com
Algaecide 60% from OMNI. This is our standard recommended treatment for algae buildup in pools.

This dreaded color of water is often caused by algae buildup. Keeping your swimming pool pump running and adding an algaecide and pool shock will usually take care of this issue. One thing to look for is the buildup on your pool’s surfaces. When algae begins to build up on the sides of your pool, it will form a protective, slime-like layer which can cause your pool shock to have little to no effect. This is why we recommend you brush the walls of your pool to break up this layer prior to adding algaecide and the appropriate amount of shock to the water.

Greenish-blue water can also be caused by high levels of copper in the pool. When this is the case, the use of metal control products such as OMNI Metal Control is required. Metal control chemicals help to break down the metals and deposit them into your filter system. Remember to keep your filter running and to retest for metal content after 24 hours. It is recommended to not shock the pool at this point, as the high oxidation could cause the metals in the water to stain your pool’s surface. After retesting, re-balance as needed.

Red-Brown Water

High metal content in your pool water can result in staining and unwanted buildup.

Iron or manganese is the most common culprit when your pool water has turned an ugly red, reddish-brown or brownish-black. If you have filled your pool with water with high metal content, the source of the water is often the cause.

The fix for reddish-brown pool water is similar to the fix for greenish-blue water caused by high levels of copper. Add a metal control sequestering chemical into your water in accordance with the label directions, keep your pump/filter running and retest for metal content after 24 hours. After re-testing, re-balance as needed.

“Pool water coloration, stains, and scale can be the result of copper, iron manganese, or calcium in the source water or from contaminants in the water. Whenever pool water coloration, stains, or scale are present, it is important to use a chelating or sequestering agent and then balance the water.”

– Pool and Spa Operator Handbook – NSPF

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Leisure Pool & Spa Supply, Inc. was founded in 1982 and is headquartered in Syracuse, Indiana. We focus on serving the service and supply needs of both residential and commercial clients. We have grown to include a branch office in Indianapolis allowing us to work with clients across the State of Indiana. Our service technicians are highly experienced and have decades of combined experience in the aquatics industry.

If you have any questions regarding your pool or aquatic center needs, do not hesitate to get in touch with us. We are always available via phone or email and look forward to assisting you. If you are looking to purchase products directly online, visit our online pool and spa supply

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