pH Drift and Salt Pools

Salt pools are great. Just ask anyone who owns or uses one. Generating and controlling your chlorine on-site eliminates the need to buy and handle chlorine tablets. In addition, the water feels soft, silky and inviting. One of the main benefits to the salt pool owner is less maintenance but this doesn’t mean that salt pools are maintenance free. You still need to test, balance and clean your pool on a regular basis.

Our chlorine generation (salt pools) customers typically have us out once a week for service and cleaning but sometimes this isn’t enough.  The National Pool Industry Research Center conducted a study monitoring salt-chlorinated pools on a weekly basis. With weekly adjustments to the chlorine levels, the pool’s free chlorine (the good stuff) remained stable throughout the study. The water’s pH, however, was more difficult to control. Every time the pH was adjusted into the “ideal” range of 7.2-7.6, it was found to drift up to 8.0 or above within 3 days or less.

Experienced service technicians have noticed this upward pH drift for several years now. Muriatic acid is the most frequently used chemical to combat this drift and lower the pH back to acceptable ranges.

It’s important to remember that your pool’s water conditions are dynamic and not static. The chemistry can change, due to many factors, in a matter of just 24 hours. As evidenced by the IPSSA’s study and our field experience, this is especially true for pH levels in salt pools. Even though we may visit your pool for service once or even twice a week, we strongly encourage our customers to take part in the water testing while we’re not there and alert us if something is out of range. 

Understanding your pool’s chemistry trends, chemical needs and characteristics is derived from frequent water testing (including your source water). What the pool owner or the pool service professional doesn’t want is a perfectly balanced and clean pool Wednesday afternoon and then potentially cloudy, scale-forming water come the weekend.

Turnover Rate

A high turnover rate is not good for business, but it is important for pools...and unfortunately often ignored in the pool construction process. Turnover in the pool industry is defined as "The period of time required to circulate a volume of water equal to the pool or spa's volume." The minimum standards for turnover are 12 hours (per ANSI/NSPI-5 2003 standards) and 6 hours for commercial pools per the standards established by the MN Department of Health.

Turnover is important because it is much easier and efficient to filter the water than to treat it with chemicals. Pools with a longer turnover time period require more chemicals to treat the water, have more issues with water clarity, are more susceptible to problems with algae and typically take longer to open in the spring.

The incremental cost to design and install a pool with good versus poor hydraulics is minimal. 2" plumbing can carry 77% more water at the same velocity than 1.5" plumbing. 3" plumbing can carry 224% more water than 2" plumbing. The incremental cost for plumbing is pennies per foot and the labor is the same. Unfortunately, we see many pools with 1.5" plumbing that provides very limited flow. When we calculate the maximum flow they can achieve through the plumbing, we know their pool has poor circulation and most likely high operating costs.

What should you do? Our recommendation is that you insist your pool or pools are built to a high standard, or a six hour turnover rate. You should also insist that your pool contractor provide a flow meter installed visibly on the equipment pad in order to verify proper flow. Most flow meters cost a pool contractor under $70.00 and are easily installed.

The pool builder should be able to tell you what flow he or she has designed but to verify, the calculations are fairly simple. The volume of water in the pool is:  Pool surface X average water depth X 7.5 = Gallons in the pool. To determine the gallons per minute to achieve a 6 hour turnover, divide the total gallons by 360. For example, a 20' x 40' pool with a deep end of 8' and a shallow end of 3' would have approximately 33,000 gallons of water. The minimum flow to achieve a 6 hour turnover rate would be 92 gallons per minute.

The IntelliFlo Pump: A Quick Reference Video

Okay, I want a pool, what are some of the issues we should consider?

Once you have established your budget for the pool and the landscaping, what other pool related questions or issues should I consider?

1. Obtain a Certificate of Survey from your local city’s planning or engineering department to see if there are any easements, set backs, or other restrictions for your property.

2. Site conditions will also affect the placement of the pool. Some of these are overhead electric lines, hill or slope proximity, septic systems, and soil conditions.

3. Where will the pool equipment be located? Pool equipment is designed to be placed outside and it is not necessary to place them next to the home. If they are adjacent to the home, they should be kept away from windows that open and your air conditioner condensing unit. In addition, the pool pump is going to work better when it is at or even below the level of the pool. The reason is that pool pumps are good at pushing water, not drawing water above two to three feet above a pool.

4. What type of pool construction is desired? Vinyl lined, concrete, or fiberglass.

5. Size and shape of the pool? Most pools in our market are rectangular to accommodate an automatic cover, but free formed pools can also have an automatic cover if properly designed.

6. Do you want a diving pool or an activity pool? The minimum water depth for a diving pool is 7’ 6”. But the national trend is for activity pools with a maximum depth of five feet.

7. If you want a diving pool and a diving board, there is a wide range of board/stand styles and quality levels. We recommend the SR Smith Cantilever stand.

8. How will you enter and leave the pool? Stairs will be used in the shallow end. Stairs add a lot of beauty to a pool and should be given careful consideration as to design and location. Some pools now also incorporate a sun shelf that is only a few inches deep to allow the placement of lounge chairs in the pool.

9. Do you want the pool to have under water lights? Options range from incandescent, to fiber optic to LED lights. The current trend is the installation of LED lights that provide color options, last longer and use a fraction of the energy of incandescent or halogen lights.

10. What type of deck and coping do you want? How much deck will you want for both walking around the pool and for pool side activities such as lounge chairs and tables – which are typically located at the shallow end of the pool.

11. If your pool will have an automatic cover, will the lid over the cover be aluminum, concrete or stone pavers? When the pool cover is closed when the pool is in use, will the cover be exposed or hidden beneath the lid?

12. Do you want to incorporate any family activities for the pool such as basketball or volleyball? You can have anchors installed in the deck (and properly bonded) so that games will be properly secured.

13. Will your pool have a winter mesh cover? These are important in our climate. If your pool deck is using pavers, you may need a concrete base under the cover to secure the anchors.

14. Do you want to have any special features such as deck or laminar jets? Attached spa? Water fall? All of these add beauty to the pool and increase the use of the of the pool beyond just our warm summer days.

15. Will your pool have an automatic cleaner? If so, will it be a suction side, pressure side or a robotic cleaner? (see our blog article on types of cleaners)

16. When your pool loses water (typically a ¼” a day in the summer due to evaporation), how will you fill it? With a garden hose? We always recommend an electronic water level controller.

17. How will the pool be sanitized and what chemicals will be used? Systems range from (least expensive ) putting chlorine pucks in the skimmer baskets to an automated chlorine generation system (which is what we recommend and install).

These are just a few of the issues you should consider before you decide on your pool.

Why is my Spa Foaming?

The formation of "suds" or foaming on the surface of your spa is typically caused by one of three factors:
 
1) Excessive amounts of lotions, deodorants and/or cosmetic products contribute to spa foaming. 
2) Aeration from the therapy jets can increase the amount of foam.
3) Low Calcium Hardness levels. This foam generally occurs when the calcium hardness level drops below 100 ppm (mg/L).

In some cases, your spa foam may be caused by a combination of 2 or 3 of these items. In any case, your first step should be to perform a full water chemical test (pH, alkalinity, metals, calcium hardness, temperature, TDS and sanitizer level). If your test kit does not test for calcium hardness levels, we suggest contacting or bringing a water sample to a pool/spa professional. If your calcium levels are too low, calcium hardness may be increased by the addition of calcium chloride (calcium increaser).

With regards to causes # 1 and # 2, a defoaming product may be used to reduce the visual effect of foam. These products typically contain silicone emulsions that will help break down the foam. Besides being visually unappealing, foam is often full of contaminants. When contaminants are allowed to concentrate, foaming similiar to dish soap will occur. If defoamers, oxidation treatments and water clarifiers don't take care of the problem, a full spa dump and fresh fill may be justified.

Please Give me a Bid...

We hear this frequently from people that just want a price on a ___ x ____ pool, ____ deep with a diving board, filter, heater, and pump. The assumption is that every pool is pretty much the same and by getting competitive prices, they will get the best “deal.” Unfortunately, what this process will most likely insure is that they will get a cheap pool, but not necessarily a good value. A good value pool will be a pool that is properly designed and built to be easier to maintain, use less chemicals, and cost less to operate.

Only specifying the size, depth and few amenities for the pool is like specifying the size of the home you want to buy or build, allowing the contractor to define how much to spend on the floor coverings, cabinets, and windows. If you want to get a well built pool that will be easy to maintain and stand the test of time, you should consider identifying the following:

1. Will the area around the pool the pool be excavated with the on site soil or will engineered soil be brought in?
2. How many skimmers will be installed? You should have at least one for every 400 square feet or faction there of a pool. For example, a 600 square foot pool should have two skimmers.
3. What is the flow rate and will they have a flow meter on pool equipment pad? A well designed hydraulic system will have a return every 20 feet around the perimeter of the pool and a turn over rate of six hours or less.
4. Will they have a single speed pump or variable speed pump?
5. Will the filter be a sand, DE or cartridge filter? Is it sized properly for the required flow? We prefer cartridge filters because they do not waste water and chemicals in the back wash cycle.
6. Will the pool have an electronic water leveler controller or will you have to fill the pool with a garden hose?
7. Will you need filtered water to fill the pool or is the source water (from the home) adequate (it should be tested in advance)?
8. Will the pool have an automatic cover and if so, what type of lid will be on the cover, aluminum, brick, or pavers?
9. How will the pool be covered in the winter, with the automatic cover or a separate winter cover?
10. If your pool is going to be built close to a hill or a slope, proper engineering should be considered for a retaining wall to prevent slope creep or differential settling.

These are just a few of the types of questions that should be considered on any pool design, or bid request.

Do I Need a CPO? What is a Certified Pool Operator?

According to the National Swimming Pool Foundation, there should be a trained and certified operator at every pool/spa facility. We strongly encourage all owners, managers and anyone overseeing the safety of a pool or spa to become certified. The owners, managers and maintenance staff, should all have a comprehensive knowledge of statutes, codes, regulations and common accepted practices. The CPO certification program will provide this educational base.

With regards to public swimming pools and spas, the American National Standards and the Association of Pool and Spa Professionals says: "Both existing and new public swimming pools and spas shall be maintained under the super-vision and direction of a properly trained operator who shall be responsible for sanitation, safety, and proper maintenance of the pool, and all physical and mechanical equipment. The operator shall be certified in accordance with state/local codes."

Essentially, any individual who evaluates and adjusts pool or spa water chemistry should be certified. Any individual who performs routine maintenance on a pool or spa should be certified. Many organizations also require head lifeguards or swimming instructors to be trained and certified. The CPO certificate is presented with the individuals name (not the facility) and is valid for 5 years. A CPO certificate also provides an individual with opportunities for advanced learning, potential promotions within an organization and even wage increases.

Whether a facility owner or maintenance technician, manager or lifeguard, the Certified Pool Operator is one thing- an aquatics facility professional.

For more information, please check out http://www.olypools.com/ or http://www.nspg.org/.