I think the answer to your question is about 3-6 days. The problem is that the chlorine that you need to keep the bacteria in check is used up more quickly as the temperature rises, the activity increases, and as sweat and other body stuff is put into the pool.
It takes a lot of chemicals to make pool water safe for swimming. Untreated water can accumulate harmful Escherichia coli and Salmonella bacteria and protozoans such as Cryptosporidium parvum and Giardia lamblia.
Swimming pools need chlorine because chlorine is the only effective way to keep pool water clean. Even a saltwater pools need chlorine (they just generates the chlorine themselves). While there are other methods of cleaning pool water, such as UV or ozone treatment, they are not replacements for chlorine.
There are alternatives to chlorine including bromine, ionizers, and ozonators, though with each you'll still need to use some chlorine. A fourth alternative is PHMB, which doesn't require the use of any chlorine. All four have drawbacks, including cost. Chlorine is relatively cheap.
Even from a health standpoint, it is simply not safe to operate a pool without some added “chemicals” to combat bacteria and contaminants in the water. A pool without chemicals is the perfect breeding ground for bacteria, viruses, and parasites.
While the quart or so of water that was setting in the hose may have some chemical contaminants in it, by the time that is diluted into thousands of gallons of water, it's of no concern. That is of course assuming that your swimming pool is not your primary source of all drinking water.
Maintenance is critical when it comes to the quality of your pool water. Well maintained pool water can last up to 5, maybe even seven years before you need to replace it. This means weekly cleaning, functional filters, and checking ph levels every day. Usage is a huge determining factor.
A pool can only be safe for swimming without a pump for a few days and a maximum of one week. The definite number of days the pool will be safe will also depend on the temperatures of the water, the weather at that particular time, the level of chlorine, and how clean the pool was before the pump stopped functioning.
Deciding when to change your pool water is important. Most in-ground pools should be drained and have the water replaced every five to seven years. How often you drain your pool depends on a couple of things: Maintenance and upkeep.
Water trucks can fill a pool much faster than a standard hose. A 25,000-gallon pool will take from 42 to 84 hours to fill using a garden hose, based on normal water delivery.
Tap water can present risks.
Most people fill their kiddie pool with hose water, which doesn't usually have enough (or any) disinfectant in it to kill germs. Since it's not recommended to use chlorine in kiddie pools, there can be an increased risk of kids catching a recreational water illness.
1. Have the water trucked in. It fills up the pool quicker and costs the same amount if using your hose. When you use your hose you have to pay sewer fees.
Baking soda, also known as sodium bicarbonate is naturally alkaline, with a pH of 8. When you add baking soda to your pool water, you will raise both the pH and the alkalinity, improving stability and clarity.
Mineral Swim is the only system of it's kind combining Australian made ozone water purification technology with 100% natural Dead Sea minerals to make it the safest, healthiest swimming pool about.
Baking soda is safe and straightforward to use, while also providing your pool with a clean, clear, sparkling water that is pleasant to swim in. Baking soda does not sting the eyes; neither can it cause drying of the skin.
Regardless of how frequently or what system you use to add chlorine to the water, the chlorine level should stay between 1.0 and 3.0 parts per million (ppm) to maintain a healthy pool. Anything higher will make you to run the risk of red eyes and swimmers itch.
Pros of Saltwater Pools
There's less chlorine and less of the heavy chemical scent and content. They're gentler on the skin, with less irritation to the eyes, hair and swimsuits. The water has a softer, silkier feel to it compared to chlorine water. They have lower maintenance costs than chlorine pools.
Short answer: yes. Longer answer: it depends on the formulation. The label on every bleach bottle should tell you the ratio of sodium hypochlorite (and available chlorine) in the bottle to everything else. A higher percentage is generally better, as you'll need to use less bleach to treat your pool.
The benefits of swimming pool salt
Using swimming pool salt instead of chlorine delivers greater swimming comfort: Swimming pool salt does not give off an unpleasant odour as chlorine does. It is much less harsh on hair and skin. It does not cause your eyes to sting.
At an average of $0.004 per gallon, city water is the most inexpensive and most popular option. For 15,000 to 30,000 gallons, you'll pay between $60 and $120.
Most people head to the hose, and that is a viable solution if you are a very patient person, have multiple hoses and are not using well water. The average pool can take 12-24 hours to fill and that is only if you have a few hoses chugging away.
If you can pump around 30 GPM (gallons per minute), which is also equivalent to 1800 GPH (gallons per hour), it should take you 2.78 hours or 2 hours and 46 minutes to drain your pool using a hose.