PVC Trouble-Shooting Guide

Bubble or fold on the PVC

Origin: unbalanced water + warm temperature + low pH

Water is unbalanced, and is inside the aggressive zone. That means there are not enough minerals inside water to have a balanced pH.
As water want to be balanced, it would find out a way to add mineral, and would dissolve a part of mineral compounds of the PVC.
Thus PVC would be less strong, and with warm temperature and pH lower than 7.0, it would create some bubbles or folds at its surface.

Way to solve the problem

• Balance the water (adjust total hardness and total alkalinity) and increase pH to allow mineral deposition inside created hole.

Black spots

Origin: unbalanced water + algae + metallic compounds

Water is unbalanced, and is inside the aggressive zone. That means there are not enough minerals inside the water to have a balanced pH. As water needs to be balanced, it would find out a way to add mineral, as result, would dissolve a part of mineral compounds of the PVC.
By removing those mineral compounds, this would create holes.
Algae would fix a part of them inside, and by consuming dissolved metallic compounds, would create metallic sulfur which gives black spots.

Way to solve the problem

• Reduce pH and shock chlorine treatment to kill any algae
• Add metallic sequestrant products
• Balance the water (adjust total hardness and total alkalinity)
• Increase pH to allow mineral deposition inside created holes

Pink spots

Origin: unbalanced water + humidity behind the cover

Water is unbalanced, and is inside the aggressive zone. That means there are not enough minerals inside the water to have a balanced pH. As water needs to be balanced, it would find a way to add minerals, and would dissolve a part of mineral compounds of the PVC.
By removing those mineral compounds, this would create holes.
Linked to the depth of those holes, water could go through the PVC and create humidity behind it.
Step by step, mushrooms would appear and create these pink spots.

Way to solve this problem

• Reduce pH and shock chlorine treatment to kill any mushrooms
• Balance the water (adjust total hardness and total alkalinity)
• Increase pH to allow mineral deposition inside created holes
• If there are too many spots, there would be no other possibility than removing PVC and treat the surface behind it with specific disinfectant

Orange/yellow spots on the water line

Origin: unbalanced water + solar cream

Water is unbalanced, and is inside the scaling zone; meaning there are too many minerals for the pH value. Thus water would create a scale deposition where the maximum of evaporation (on the water line) can be found.
This scale deposit would help solar cream and cosmetics products to be fixed on the PVC.
Their organic solvent would react with UV light and would create yellow/orange spots on the PVC.

Way to solve the problem

• Clean the water line with an acid and degreaser product
• Balance the water (adjust total hardness and total alkalinity)
• Reduce pH to avoid mineral deposition
• Add anti scale products to limit its chemical deposition
• If spots are still there, brush the water line with non-stabilized chlorine inside a cotton socks. Thanks to its high pH value it would remove grease and organic solvent and chlorine would remove the spots

Green spots on the PVC

Origin : unbalanced water + algae

Water is unbalanced, and is inside the scaling zone; meaning there are too many minerals for the pH value.
Thus step by step, water would create a scale deposition everywhere on the bottom of the pool.
This scale deposit would help algae be fixed on the PVC, mostly on the corner as there is less water movement.
Those algae would spread over and inside scale deposit, and would be very difficult to remove.

Way to solve the problem

• Reduce pH and shock water with chlorine. Then add anti-algae to limit algae spreading.
• Balance the water (adjust total hardness and total alkalinity)
• Reduce pH to avoid mineral deposition. Then add anti scale product to limit its chemical deposition.

More information on water balancing available on our Acti Chemical: Water balance.