By Karen Rigsby

Editor’s note: Due to the seasonality of the pool and spa industry and the transient nature of the business, the water treatment information provided in this article can be shared with service technicians who are new to the job.
Spring can be an exciting time for pool owners. Everyone looks forward to opening the pool and another season of making many family memories. However, pool opening is often quite stressful—especially for maintenance technicians new to the job—as problems may arise that were not anticipated and, in some cases, can be difficult and frustrating to handle. Many times, these issues can be avoided if dealt with appropriately during the off-season, and more so if the pool is closed properly. In the event there are water quality problems, they can be handled with the proper steps and a little patience.
When opening a pool, there are a few universal steps that should always be taken; however, before worrying about the water, it is important to handle all of the physical maintenance aspects first. This means making sure all of the equipment is working properly. If the pool was covered, every attempt should made to remove it without allowing debris (on top of the cover) to enter the pool. Once the cover is removed, it should be cleaned and stored properly. If the pool was partially drained, it needs to be filled to the appropriate level before the equipment is started. All of the equipment should be inspected for leaks or damage and the manufacturer’s instructions for start-up procedures should be followed.
Once the equipment is operating properly, it is then time to deal with the water. However, before taking a water sample, the pool should be allowed to circulate for 24 hours as there are certain components of the water that will stratify or end up in layers.

For example, heavier components will end up at the bottom; therefore, taking a water sample prior to circulating the water will skew any test results and cause improper recommendations. Once the water has circulated and is tested properly, it can be balanced and then any problems can be handled appropriately.
It is recommended the total alkalinity is balanced first, and then the pH, followed by the calcium hardness. The stabilizer should also be tested and adjusted if needed; however, many pools are in a chlorine-demand state upon opening. Pools in this condition will often produce false-negative test results.
In other words, the stabilizer is present, but in some instances it will not show up on tests when the pool is in a chlorine-demand state. This phenomenon is not completely understood; however, it does happen frequently. Once the chlorine demand has been treated, the stabilizer will show up on the test. For this reason, chlorine demand issues should be treated first, then the water should be re-tested so the stabilizer can be adjusted (if necessary).
The remainder of this article will focus on specific problems, solutions, and preventative measures for some of the more common issues often faced during pool openings.
Problem: Algae growth
Cause: Algae can begin to proliferate over the course of winter, especially in warmer climates or those regions with mild winters. Green algae are the most common type found in pools upon opening. In fact, more than 7000 different species exist. Approximately 10 per cent of these are marine species (found in the ocean) with the remainder being found in lakes, rivers, ponds, and pools.
Green algae are named for the chlorophyll (the molecule that captures light energy to carry-out photosynthesis) in the cell which gives them their green colour. Green algae can be free-floating or surface clinging and can be found in all pool types. They are typically the easiest to treat; however, some species may be more difficult to manage than others. Interestingly, although plants generally need light to proliferate, there are many species that will grow with little to no light available. They can proliferate in covered pools and on filter beds.
Treatment: If the pool is swampy, a floc should be added first as it will drop material to the bottom of the pool so it can be removed by vacuum. Once this has been completed, the water balance should be checked and adjusted (if needed). A chlorinating product should also be added to raise the chlorine levels above one part per million (ppm), then an algaecide should be applied. It is best to run the pump 24 hours per day while treating the pool for algae to help clear the water faster. Using a clarifier will also help to polish the water as the treatment
is being completed.
Prevention: The pool should be closed properly to ensure the water is balanced and has a chlorine residual—preferably on the high end (approximately 4 ppm). A winter algaecide should also be added. In milder climates, or those with warmer winters, a mid-season treatment will be necessary. In the spring, starting the pool on a program that includes the use of a maintenance algaecide will help to prevent algae throughout the season.