What is blue crystal and how do you get it off of your Gunite or Diamond Bright Pool?

Blue crystal refers to copper sulfate, which is a chemical commonly used to treat algae in pools. However, if not properly managed, copper sulfate can accumulate on the surface of Gunite or Diamond Bright pools, forming a blue or turquoise stain.

Here are some steps to remove blue crystal stains from your pool:

1. Identify the Stains:

Before attempting to remove the stains, identify and confirm that they are indeed blue crystal stains. Copper sulfate stains are usually bright blue or turquoise in color.

2. Check Water Chemistry:

Make sure that the water chemistry in your pool is balanced. The ideal pH range for pools is between 7.2 and 7.6, while the ideal chlorine level is between 1 and 3 ppm. Proper water chemistry can help prevent the formation of stains.

3. Brush the Pool Surface:

Use a soft nylon brush to gently brush the surface of the pool, particularly the areas where the blue crystal stains are present. Brushing can help loosen up the stains and make them easier to remove.

4. Use Sequestering Agents:

Sequestering agents are chemicals that help bind metal ions, such as copper, and prevent them from forming stains. Apply a copper sequestering agent according to the manufacturer's instructions.

5. Drain and Refill:

In severe cases where the blue crystal stains are extensive, you may need to partially or completely drain the pool and refill it with fresh water. This can help remove the copper sulfate buildup and give you a clean slate to start over.

6. Preventative Measures:

To prevent future blue crystal stains, use copper-based algaecides sparingly. Follow the manufacturer's instructions carefully to avoid overdosing. Additionally, maintain proper pool chemistry and regularly brush the pool surface to prevent the accumulation of debris and potential metal stains.

NOTE: If the blue crystal stains persist despite these efforts, it's recommended to consult with a professional pool service company for assistance.