In most cases, the walls and floor of your pool feel slimy and slippery due to a lack of pool maintenance. Water chemistry is important in order to maintain clear and bacteria-free water. Generally, slippery and slimy pool walls are an early indication of bacteria and algae growth.
The slimy and often smelly film that floats on the water's surface is a distinct green color, so look carefully for it before going for a swim. If there's an off-smell, don't go for a swim and don't let your dog take a plunge either.
You can use either a chlorinated product or a non-chlorine shock oxidizer to break down combined chlorine in the water. Shocking the pool can also remove excess bather waste and visible algae. Shocking should be done when combined chlorine levels exceed 0.5 ppm.
Although inflatable pools don't need to use chlorine, it's one of the most common ways to keep pool water sanitary and safe to swim in. The chlorine is used to efficiently kill bacteria in the water that may be harmful to swimmers. Larger inflatable pools will benefit the most from the use of chlorine.
Small inflatable or plastic kiddie pools and water slides don't have the same protection against germs that a swimming pool, hot tub, or water playground do. That's because it is unsafe to add germ-killing disinfectants, such as chlorine or bromine, to the water in kiddie pools and water slides.
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.
For most inflatable pools or plastic kiddie pools following the guidelines listed above, the water should be changed every two weeks at a minimum. If you are not adding chlorine to kill bacteria, drain the pool every other day. Stagnant water without chlorine can become unhealthy water in as little as 24-48 hours.
For the greatest protection against algae, bacteria, and cloudy water, Intex pools should maintain a chlorine level of 2.0-4.0 ppm at all times.
When to Replace the Pool Water
You should replace pool water every five to seven years. As much as possible, you should drain and refill your pool during mild weather. It's to avoid pool damage caused by direct sunlight and heat. Moreover, a pool maintenance company can recommend the ideal time to drain your pool.
If you simply do not want to use chemicals to keep your kiddie pool clean, there is an alternative. Rather than chlorine, use Distilled White Vinegar. Add 1/2 Cup for every 100 gallons of water in your pool.
You simply place your chlorine tablets in the floater (based on gallons of water in your pool), and it does the work for you. The downside to a chlorine floater is that it is a passive system, so sometimes it can get stuck in one spot for a period of time.
With Chemicals
If you utilize some chemicals you can keep your kiddie pool water for much longer. If your children use the pool on a daily basis, empty the water every month. If your children use the pool infrequently, wait a month and a half to two months before changing the water.
WADING POOL DISINFECTION
When chlorinating wading pools, use 1/8 cup per 100 gallons of new water. Mix required amount of Clorox® Regular Bleach2 with 2 gallons of water and scatter over surface of pool. Mix uniformly with pool water. Empty small pools daily.
There are two main causes of oily film on your water: hydrogen sulfide, and iron bacteria.