There are very few reasons why a person should ever need to drain their swimming pool. In reality, pool draining is risky and can cause extensive damage. Thanks to improving technology in the industry, pool owners now have alternative water treatment options to help avoid the risks of draining. As a result, residential pools can last longer than ever before!
Swimming pools are designed to be full of water and are structurally unsound when empty. When a swimming pool is drained there are three adverse things that can happen. To start with, the shell will etch each time it is drained. Plaster pools are especially notorious for becoming porous the more often they are drained. This gives place for algae to grow, and sometimes the only way to fix this damage is to re-plaster. The second risk is cracking or popping of the shell. This can occur in both plaster and pebble pools. Sections of the shell can pop out and fall off, and small to large cracks can appear. The third risk is due to hydro-static pressure that can build up under the pool. When the pool is empty and the pressure is greater under the pool than above the pool, the whole thing can lift/float up out of the ground. In this case the damage is often irreparable. These risks can be completely avoided if the right water treatment is chosen. Understanding the reasons why a swimming pool should be drained and the alternative options available is the first step to avoid undue damage.
Green pool water does not need to be drained. This is the most common reason where pools are drained unnecessarily. The contributing factors to algae growth are lack of chlorine and abundance of phosphates in the water. Once these two things are taken care of, with quality algaecide and phosphate remover, the water should return to its normal state. For the most part, a decent pool with a working filter should be able to clean up even the greenest of water by itself. It will take time, attention and proper chemical balance, but green water can almost always be transformed into crystal clear water without draining.
High levels of combined chlorine, sometime referred to as chlorine lock, is a phenomenon that can take place. When chlorine added to the water does not have the desired effect of disinfecting it is usually due to combined chlorine. A common denoting characteristic is the strong “chlorine smell” that is detectable around the pool. When levels of cyanuric acid are over 80 ppm, or when PH is not balanced, there is a higher risk of this occurrence. A common condition is that chlorine will molecularly bond to cyanuric acid and other unwanted chemicals and will not leave a sufficient amount of chlorine free to destroy the organic substances in the water. Traditionally, the only way to remove the cyanuric acid is by draining and refilling. Thanks to recent advancements in pool care techniques, it is possible to extract cyanuric acid and combined chlorine from the water without draining. Reverse osmosis is sometimes used to achieve this. Ion exchange treatments units will also remove the contaminants from water and will eradicate chlorine lock. This is achieved by recycling the water through activated carbon filters coupled with ion exchange units.
Hardness causing substances compound over time with evaporation and chemicals added to the water. High levels of hardness causes damage to swimming pools. Evidence of high calcium levels can be seen by white deposits on the tile around the water line of the pool. If the calcium is especially high, calcium deposits can even form underwater on the shell of the pool. If the calcium gets too high (over 500 ppm) and leaves deposits it may be necessary to hire a tile cleaning company to remove the scale around the water line and spillway areas. If calcium nodes have formed underwater it may be necessary to chip and re-plaster the pool. It is much better to avoid these problems by keeping calcium levels low. A common, outdated method to reduce the calcium levels is to drain the swimming pool and refill it again. As previously discussed, this is potentially dangerous and can cause damage. The same alternative “no drain” methods that are used to lower cyanuric acid levels are effective in reducing calcium hardness as well.
Given the risks involved with draining, the only legitimate reason to do it is to make repairs on underwater components or to acid wash the interior of the pool. Even these procedure can be done without draining in most situations. In this day and age it is a safer and smarter to avoid the risks of pool draining altogether and choose a no-risk alternative.
The first of the two alternatives to draining is reverse osmosis. Reverse osmosis on a swimming pool is performed by running the water through a large RO system housed in a trailer. The water is recycled back into the pool free from cyanuric acid and unwanted chemicals. Calcium levels can also be brought down to a lower, balanced range. The downside: it does not conserve all of the water and some of it is lost in the process. It is also a bit pricy for most pool owners to consider.
The second alternative to draining is ion exchange. Ion exchange employs the use of commercial grade water softeners along with activated carbon filters to filter out contaminants and hardness. The water is recycled through a system that is generally set up next to the swimming pool and runs silently for about 12 hours. All of the water is conserved and the unwanted chemicals are removed along with calcium harness and cyanuric acid. The calcium hardness is brought down to 150 to 200 parts per million leaving the swimming pool with sparkling healthy water. This treatment is more affordable than reverse osmosis.