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. If left untreated, this can turn into a bigger problem that will take more resources and effort to cure.
Clean the Filter
The slimy feel on your pool walls is an early indication of algae growth. To stop algae growth in its tracks, clean the pool filter first. Before adding any chemicals to the pool, make sure you have a clean filter. Cartridge, sand or diatomaceous earth filters all have their own backwashing methods for cleaning. Backwashing flushes the filter free of the dirt and debris it has collected over the course of normal operation. A clean filter helps the circulation of chemicals and prevents bacterial growth.
Test the Water
The filter should be running after you backwash it. Use a testing kit or testing strips, both of which are available at your local pool supply retailer, and determine what aspects of the water chemistry need to be adjusted. The water will feel slimy in many cases when the temperature exceeds normal range, such as during a heat wave. The warmer the temperature, the faster chlorine dissolves in the water. Add enough chlorine to bring it into the normal range as indicated by the testing kit.
Pool supply retailers suggest using algaecide as part of your regular pool maintenance schedule. Many people have the misconception that algaecide is effective once algae has bloomed in your pool. This is not the case because algacide is most effective as a part of regular maintenance to prevent the growth of algae. If slimy pool walls are a regular occurrence, start using algaecide routinely. Algaecide will only help, not hurt, your pool. Just do not add too much because it can cause suds in your pool.
Brush and Shock
Algae are microorganisms that thrive in bacteria-ridden water. Slime is a good indication that bacteria have taken over and need to be controlled. Brush the pool floors and walls with a pool brush then add a shock treatment to the water, taking into account your pool's water capacity. Shock treatments are sold in both granular and liquid forms and can quickly bring sanitizing levels up to kill bacterial growth.