Maintaining a pristine pool requires understanding and addressing various types of stains and issues that can affect its appearance and longevity. This comprehensive guide covers three common concerns: organic stains, metal stains, and calcium leaching. Each section provides insights into identification, removal, and prevention strategies to help you keep your pool in optimal condition.

 

Organic Stains

Identification:

Organic stains are typically caused by natural debris such as leaves, berries, algae, or other plant matter that settles in the pool. These stains often appear as greenish-brown discolorations on the pool surfaces. To confirm an organic stain, you can rub a trichlor (or chlorine) tablet on the affected area; if the stain lightens or disappears, it's likely organic in nature. 

Removal:

1. Balance the Water: Ensure the pool's alkalinity is between 80 ppm and 120 ppm, and the pH is between 7.2 and 7.6.

2. Shock the Pool: Apply a granular chlorine shock treatment according to the product's instructions, preferably overnight to maximise effectiveness.

3. Brush the Pool: Thoroughly brush the stained areas to help remove the organic material.

4. Run the Pump: After leaving overnight, operate the pool pump throughout the day to circulate the water and distribute the shock treatment.

5. Repeat if Necessary: If stains persist, repeat the process until the stains are eliminated.

Prevention:

• Regular Maintenance: Keep the pool clean by skimming the surface frequently and vacuuming the bottom to remove debris promptly.

• Water Balance: Maintain proper water chemistry, focusing on alkalinity, pH, and sanitiser levels.

• Landscape Considerations: Position fruit-bearing trees and shrubs away from the pool area to minimise debris.

• Routine Inspections: Regularly check for and address any stains early to prevent them from setting.

 

Metal Stains

Identification:

Metal stains result from metals like iron, copper, or manganese entering the pool, often through corroded pipes, metal accessories, or certain algaecides. These stains can manifest in various colors:

• Copper: Blue, green, or teal stains.

• Iron: Reddish-brown or rusty stains.

• Manganese: Pink, purple, or black stains.

To test for metal stains, rub a vitamin C tablet on the discolouration; if it lightens or disappears, metals are likely the cause. 

Removal:

1. Test for Metals: Use a metal test kit or consult a pool professional to identify the specific metal causing the stain.

2. Lower Chlorine Levels: Reduce chlorine to below 1 ppm before treatment, as high chlorine can interfere with stain removers.

3. Apply Metal Stain Remover: Use a product containing ascorbic acid or a similar agent, following the manufacturer's instructions carefully.

4. Monitor and Adjust: After treatment, re-balance the water chemistry, paying attention to pH, alkalinity, and sanitiser levels.

Prevention:

• Source Water Check: Test fill water for metals and treat if necessary before adding to the pool. Generally, you'll use your garden hose which could potentially be drawing water from corroded pipes.

• Maintain Equipment: Inspect and replace any corroded metal components in the pool system.

 

Calcium Leaching

Identification:

Calcium leaching occurs when water with low calcium hardness seeks to balance itself by drawing calcium from pool surfaces, leading to etching, pitting, and a rough texture. This is often due to aggressive or "soft" water conditions.

Prevention:

• Maintain Calcium Hardness: Keep calcium hardness levels within the recommended range of 200-400 ppm.

• Regular Testing: Frequently test water chemistry to ensure all parameters, including pH, alkalinity, and calcium hardness, are balanced.

• Use Calcium Increaser: If calcium levels are low, add a calcium hardness increaser to the pool water as directed.

• Avoid Soft Water: Do not use softened water to fill the pool, as it can exacerbate calcium leaching.

Removal:

   1. Scrape With Chisel:

• • A simple, yet non-traditional approach. Physically scraping calcium off the surface is possible in some situations. If completed successfully ensure calcium levels remain in range.

   2. Acid Wash (If Necessary):

• • If calcium leaching has caused significant etching or surface damage, an acid wash may help restore the surface.
  • Acid washing should be done cautiously as it removes a thin layer of the pool surface. Hire a professional if you're unsure how to do this safely.
  • See our guide on how to Drain & Acid Wash your pool.