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.
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.
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.
If possible, store inflatables in their original packaging; otherwise place them in individual boxes, plastic containers or zip-up storage bags. Choose storage bins or mesh bags for small toys, goggles, snorkels and water guns and noodle caddies for pool noodles.
In fact, bleach is often recommended for emergency water disinfection, so reasoning suggests it can work well in a kiddie pool. However, not much bleach is required to properly sanitize a given amount of water.
A simple and non-toxic way to clean a paddling pool is to clean it with white vinegar. White vinegar is great for cleaning because it can remove all the horrid bacteria that sets up up home in your paddling pool. It's also colourless, so it won't stain the pool either.
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. If you opted for the Intex Salt Chlorinator, you can make your own chlorine by adding the correct amount of Pool Salt to the water.
Most large inflatable pools that need chlorine to be kept clean will be fine with just some chlorine tabs. There are other chemicals in most chlorine tabs like, cyanuric acid, to help make the chlorine last longer.
The water of your paddling pool can also be maintained using Milton Sterilising Fluid.
Make your own homemade cleaning solution either using one part bleach to five parts of water, or equal parts of vinegar and water. Adding a little bit of the solution as you go, clean the sides of the pool using a scrubbing brush.
Salt is often presented as a healthier alternative to adding chlorine to a kiddie pool, since saltwater is gentler on the skin.
To keep the pool clean without a filter, it is necessary to use chlorine with a flocculant or to use a flocculant chemical. This product groups the impurities that float in the water, causing them to fall to the bottom of the pool so that they can be removed later with a cleaner.
Make sure your inflatables are clean, dry, and undamaged. Roll them up properly and store them in vinyl storage bags. Keep them someplace warm, clean, dry, and preferably off the ground. Don't expose them to rain or snow.
“Soft Gear” Softer items such as inflatables & PFD's should be stored in “critter proof” boxes or plastic tubs. It's also important to keep them in a dry, climate-controlled place, out of the way of excessive cold, heat, exhaust, chemicals, or fumes.
Skimmer Net
With excessive debris in the water like leaves, pine needles, and dirt, the pool walls will get slimy and grow mildew faster.
“It's important to change the paddling pool water every day – drain it and let it dry at the end of the day and use an anti-bacterial spray to kill any germs so it is safe to use the next day.”