Several factors can contribute to foaming in pools:
- Soft water; low calcium hardness levels.
- High TDS levels.
- Lotions, oils and animal fats in the water.
- Poor water balance.
- Low grade algaecides. 10% polymers.
- Tile cleaning phosphates.
- Use of aeration (air jets) in biguanide treated pools.
Correcting the above conditions can reduce or eliminate foaming. Anti-foaming agents are available.
Chitin products like Sea-Klear can prevent or eliminate foaming from occurring. The Natural Chemistry line of enzyme products are also very effective anti-foam agents. Sometimes balancing the water and "shocking" the pool can remove the foaming.