Poolside by CGT Vinyl Pool Technical Manual

What Causes Stains or Algae on Vinyl Pool Liners?

Understanding pool liner stains and algae growth helps pool owners identify problems and apply the correct treatment. Poolside by CGT identifies stains and algae as common issues that can be minimized through proper maintenance and balanced water chemistry.

Organic Stains

Organic debris such as leaves and insects may leave brown stains on vinyl liners.

These stains often respond to chlorine treatment.

Metal Stains

Metals such as iron, copper, and manganese can cause staining.

One diagnostic method involves applying vitamin C tablets (ascorbic acid) to the stained area. If the stain lightens, it may indicate metal staining.

Algae Stains

Algae can appear when sanitizer levels drop too low. Black algae can be particularly difficult to remove.

Green Algae

Mustard Algae

Black Algae