Green water is generally caused by one of two problems, Algae which are slimy or Copper staining which is manifest as water discolouration.
Algae
Whilst not harmful, these microscopic organisms are unsightly, and when you see them in the water are millions!! Barren sanitiser periods (holidays/winter) and rain falling from vegetation (trees) contribute to algae infestation.
Treatment
- Adjust pH to 7.2 – 7.6 range (remember chlorine efficiency is impaired in high pH levels above 7.6)
- Ensure cyanuric acid/stabiliser levels are 100 or below, for improved chlorine effectiveness
- Turn the circulation system on, prior to shock treating the pool with Shock Granules or Sodium Hypochlorite to min. 5ppm
- Apply algaecide – Super Algaecide/Liquid Algaecide whilst circulation is still running for good distribution.
- Observe impact and if algae persist due to heavy contamination repeat above.
- Remove dead algae (white residues) using clarifiers – where contamination was dramatic full floc treatment with granular floc or alternatively use Super/Ultimate Water Clarifier whilst the system is running for filter entrapment of dead Algae. (Remember to frequently backwash the filter to remove the build up of dead algae on the filter)
Cure
Consider routine use of algaecides as outlined in Summer Ideals to prevent algae blooms and costly remedial procedures as above – Super Algaecide is a favourite, but if you cannot attend to the pool often, then use Long life Algaecide
Copper Staining
Consider the source of the copper before remedy – it could be from the equipment (e.g. heat exchanger) or from copper based algaecides. If it is the former then it is usually caused by acidic conditions prevailing as aggressive water, and regular pH checks and periodic water balance is recommended.
Treatment
- Copper is stable in waters with middle pH bands, so adjust the pH to the ideal range 7.2 – 7.6.
- Stain & Scaled Inhibitor or Multi Stain Remover to gradually remove any recent staining from pool walls or surrounds.
- Assist filtration removal by using Sparkle Tablets in the skimmer, and enhance backwashing procedures in the first month after treatment.