Cloudy or milky swimming pool water is caused by seven main issues: improper levels of chlorine, imbalanced pH and alkalinity, very high calcium hardness (CH) levels, faulty or clogged filter, early stages of algae, ammonia, and debris.
For the most part, yes. It can be unattractive and it should be addressed, but it is mostly safe to swim in cloudy water. The only exception would be if the pool is cloudy because there are too many chemicals in it. This pool water would be unsafe to swim in and should be avoided.
Excessive levels of pool chemicals can cause your water to become cloudy. High pH, high alkalinity, high chlorine or other sanitisers, and high calcium hardness are all common culprits.
However, sometimes a balanced pool will become cloudy immediately after being shocked. This typically clears quickly on its own and shouldn't be considered a problem. Environmental factors include pretty much everything around the pool like severe weather, wildlife, construction, trees, pool algae, and people.
How long does it take for a cloudy pool to clear? Depending on how cloudy your water is, it may take 2-3 days for your water to clear. If you're using a clarifier, you'll need to run your filter 24/7, keep your water chemistry balanced, and add the proper amount of water clarifier every other day until it's clear.
Pool water with a high total alkalinity (TA) is often associated with cloudiness. This is because it can cause an imbalance in the pH levels and lead to calcium scaling. Typically if your TA is higher than 200 ppm, you're at risk of a cloudy pool and just like imbalanced pH levels, your chlorine will be less effective.
Baking Soda
Most remedies call for adding additional chlorine into the water. If your water's pH balance is between 7.2 and 7.5, however, you can add baking soda to the water to help clear it up. This serves as a replacement for chlorine because baking soda is a natural cleaning agent.
If the chlorine smell is very strong, however, you may soon spot “red-eyed” swimmers emerging from the pool. That's when the pool water is assumed to have “too much chlorine” in it. Ironically, a strong chemical smell around the pool and “swimmer red eye” may be signs that there is not enough chlorine in the water.
The water's pH may be too low or too high.
Lower than 7 indicates an acidic pool, but higher than 7.8 is too alkaline. A pool measuring at either extreme will likely be cloudy. High pH often indicates excess calcium deposits, and low pH often indicates more chloramine and less free chlorine.
Skim the top of the pool for debris that may have settled on the pool surface. Add one pound of diluted granular shock to the water for every 7,000 gallons of pool water. Run the filter for 24 hours and retest the water. The slimy looking film can be an early onset of algae.
Run your filtration system for eight hours every day over summer. Back-wash it if you have a sand filter and clean cartridges with Filtrite Filter Cleaner and Degreaser. Add 50 grams of Sanit-eezy Performance per 10,000 litres of pool water. No-one should swim for at least 30 minutes after this.
But excessive exposure to chlorine can cause sickness and injuries, including rashes, coughing, nose or throat pain, eye irritation and bouts of asthma, health experts warn. Instructions for safely chlorinating a pool usually call for a maximum of four parts per million when people are in the pool.
Raise the Level of Pool Chlorine
Raising pool chlorine can be much easier than trying to lower chlorine levels. Simply adding chlorine in the form of chlorine tablets, granular chlorine, liquid shock or powder shock will increase the total amount of chlorine within the pool.
Chlorine at high levels is corrosive so it's not a matter of if, but when. In particular, the chlorine dissolves the rubber and corrodes the plastic parts of pool cleaners, pumps and filters. It can also damage pool heater internals, as well as valves and rubber seals. This damage can be expensive.
The simple answer is No. Baking soda cannot be used to clear up a cloudy pool because it is a base. Bases raise PH levels, which causes the water to turn cloudy. Some people suggest using baking soda as a quick fix to high alkalinity levels, but it's not reliable as a pool chemical.
Here is why: Sunlight is white, which is made up of all the colours of the spectrum. The molecules in pool water absorb light from the red end of the spectrum when sunlight falls on the water. By removing the red, the light which ends up being reflected has a slightly blue hue which can vary in richness by water depth.
But is it safe to swim in a pool with algae? Whether mild or severe, it isn't recommended. Significant amounts of swimming pool algae welcome a breeding ground of harmful bacteria that feed on algae. These bacteria pose health risks to swimmers, most commonly resulting in a skin rash.
Proper chemical balance and sanitizer levels will prevent many opportunities for algae to bloom. High pH and low chlorine (or other sanitizer) can give algae a great start.