Cloudy Pool Water Issues – Part II


Some would say that sequels are blog box office poison, never quite as good as the original. However, Part II of Cloudy Pool Water Issues is not a sequel, but a prequel.

In Part II, we’ll explore more in detail the causes of what led to cloudy pool water in the first place.

Before we begin Part Deux, let’s review some of the lessons of Cloudy Pool Water Part I.

>>> If your pool water is cloudy, something is wrong with either your Sanitation, Circulation or Filtration. One or more of these three are not doing their jobs. We list a number of ways to improve the effectiveness of these vital functions.

LANGELIER-SATURATION-CHART>>> Also of note in Part I, was the influence of proper water chemistry on water clarity. We introduced the Langelier Saturation Index as a way to check your pool’s propensity towards scaling or corrosive water.

The Index incorporates water temperature into the calculation, which plays an important role in water clarity. Ideal pool water balance fluctuates from spring to summer to autumn, because of the effect of water temperature on dissolved solids.

Cloudy Pool Water Issues – Part Deux!

Hat Tip to David, who wrote a wonderful post recently on the 50 causes of pool algae. Many of the reasons for cloudy water are quite similar, and I have reworked his list into 50 ways to cloud your pool.

If your pool is currently hazy or milky blue, there are likely multiple reasons why…

50 Causes of Cloudy Pool Water

Pool Water Chemistry

  1. Inconsistent chlorine levels, below 1.0 ppm
  2. High combined chlorine levels, above 0.3 ppm
  3. High pH levels, rising above 7.6
  4. High alkalinity levels, above 150 ppm
  5. High calcium levels, above 400 ppm
  6. High cyanuric acid levels, above 100 ppm
  7. Very high total dissolved solids, over 10000 ppm
  8. Heavy use of calcium based pool shock
  9. High levels of particulate matter, i.e. dead algae, pollen, dust
  10. Adding more than one chemical to the pool at a time
  11. High saturation index as pool water gets warmer
  12. Using chlorine products in a Biguanide treated pool

    Pool Water Contamination

  13. Dead remains of previous algae blooms
  14. Using low grade pool salt with impurities.
  15. High levels of phosphates or nitrates
  16. Heavy use of Quaternary Ammonium algaecides
  17. Dirty pool, lots of leaves, debris
  18. Urine, Sweat, Fungus and bacteria from swimmers
  19. Tanning oils, cosmetics and hair products
  20. Run-off from nearby lawn or planters
  21. Sap and pollen from overhanging trees

    Equipment Problems

  22. Pump impeller is clogged or broken
  23. Pump not running long enough each day
  24. Pump is too large for the pool filter
  25. Pump is overheating and cycling on/off
  26. 2-speed pump, operating only on low speed
  27. Pump basket or skimmer baskets full of debris
  28. Low water level, drawing air
  29. Stuck skimmer weirs, drawing air
  30. Air leak on pump, drawing air
  31. Poor circulation in a large pool
  32. Filter is too small for pool size or pump size
  33. Filter is not being backwashed fully or properly
  34. Filter cartridge not seated properly, or missing parts
  35. Filter cartridge or filter sand needs replacement
  36. DE filter is leaking DE powder into the pool
  37. DE filter with too much or too little DE powder
  38. DE filter grids are clogged with oil or minerals
  39. Multiport valve is recirculating or bypassing filter
  40. Suction or return valves are closed or clogged
  41. Salt chlorinator cell needs cleaning
  42. Salt chlorinator cell needs replacement
  43. Salt level in pool is too low for salt cell
  44. Tablet chlorinator is gummed up
  45. Tablet chlorinator has an air lock

    Other Problems…

  46. Rough pool surface, not being brushed regularly
  47. Fresh pool plaster (will dust-up for about 6 months)
  48. Swimming pool paint dissolving, from low pH & alkalinity
  49. Too many swimmers, over 1 per 50 sq ft of area
  50. Dogs, ducks or other animals using the pool regularly

Cloudy pool water has many causes, and frequently more than one.

Attack it methodically by checking for contaminants, ensuring your equipment is operating properly and the water chemistry is dead on, and your pool water clarity will return in no time!

And there’s no shame in using coagulants to help things along!

Dr. Pool

Dr. Pool


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