What Makes Pool/Spa Water Change Color and How To Fix

Posted on May 16, 2016

Have you ever added your normal shock treatment then watched in horror as your pool or spa turned purple, black, red or green? You are not alone. This is actually a very common occurrence and usually indicates that there are minerals (metals) in your pool. The change in color is caused by a chemical reaction that occurs when the chlorine/shock oxidizes the metals in your pool water.

The following steps can be used as a guide to help you clear the odd color from your pool and help prevent it from reoccurring

STEP 1 – Determine which metals are present and the source of their presence in the pool. Your local pool store (LUSK POOLS) can test the water for you. In most cases the metals present are from the water source (well or city/county water), however many algaecides contain copper and over use can be an issue.

green tint

Green water is normally an indication that there is copper or iron in your pool water. If it is a thick dark green and the water is cloudy, then you most likely have algae not metals and should contact your local pool store (LUSK POOLS) for advice on how to rid the pool of algae. (look for an upcoming blog post covering this subject)

rusty water
Red or brown water can indicate the presence of iron, copper or maganese.

Black or Purple water usually indicates the presence of maganese. If there are black spots along the pool walls you most likely have black algae.

STEP 2 – Now that you have determined the cause of the problem it’s time to treat your pool. A metal remover should be added. Be sure that read and follow the directions on the bottle.

metal free

STEP 3 – Allow your pool/spa to run for 12-24 hours, the discoloration should begin to clear. If there is only a slight improvement then a second application of metal remover will be required.

STEP 4 – After the water discoloration has improved, turn off the pump and filter. Brush down all pool surfaces (walls, bottom and steps). Leave the pump and filter off for 12-24 hours to allow everything to settle to the bottom.

STEP 5 – Now that everything has settled, vacuum the pool on waste to get the debris out of the pool and not into the filter. If the source of the metals was your water supply you may need to use the metal remover on a weekly/monthly maintenance to prevent the discoloration from reoccurring. There are also filters which can be attached to your fill hose to pull metals and other contaminates from the water before it enters the pool.

STEP 6 – If you notice staining of the pool surfaces from the metals, use a stain remover to treat the whole pool and remove the stains.