It is frustrating when dealing with milky / cloudy swimming pool water. Sometimes very simple things cause cloudiness, but sometimes more complex things such as chemical imbalances will require professional help.
One of the most common causes for milky / cloudy water in swimming pools is misplacing the return inlet fitting's eyeball. If misplaced it will send the filtered water back into the swimming pool at an angle that does not allow water to circulate through the entire swimming pool. For example a bad angle for the inlet fitting is to have it shooting the water directly across the surface. This filtered water just swirls around the surface of the water and goes back through the skimmer and gets re-filtered. This causes the water below the surface to never make its way through the filtering system, which in return causes cloudy water.
Adjusting a swimming pool inlet fitting is fairly easy and requires very few tools. Just loosen the outer nut or ring that holds the eyeball in place. Reposition the eyeball, preferable facing towards the bottom of the pool and away from the skimmer. This is the best position to ensure all water circulating through the pool will make a journey through the filtering system. After re-positioning the inlet fitting tighten the outlet nut or ring. Results should be noticeable in about 30-45 minutes. If cloudiness improves but not drastically, you can always reposition the inlet fitting again.
It is important to figure out the reason that the water is milky / cloudy. Salt water swimming pools can reach a saturation point where it cannot hold another thing. An example of this is adding sugar to a glass of ice tea. The tea will hold mass amounts of sugar as long as it is being stirred until it is dissolved. Once the tea reaches its saturation point, the sugar will no longer dissolve into the tea. The same principle can happen to your salt water swimming pool. You should not let your swimming pool reach this point because it is hard to reverse the effects.
If adjusting the swimming pool inlet fitting did not correct the problem, a few examples of other things to look for include (but not limited to):
- Dead algae left in the pool
- Live algae
- Inconsistent chlorination
- Pool water (has not been replaced in 5 years)
- High calcium
- Low water level, allows skimmer to suck in bubbles along with water.
- High levels of urine
- Filter needs to be cleaned
- Too much rain water
- Pine sap (from surrounding trees)
- Dust blown into pool
- Possible vandalizing - dish soap, laundry detergent, etc.
- Pump not working properly
- Stabilizer too high
- Pump strainer basket too full (needs to be emptied)