Achieving Ultimate Water Clarity

Operating a sustainable aquatic facility is exceptionally important these days. Managers are seeking new methods to achieve the ultimate in water quality, combined with energy-efficient technology. While a marriage of the two is ideal, the priority is to strive for clean, clear healthy water all day, every day.

Water clarity can be verified in several ways. Most health departments suggest that pool clarity is determined if the main drain can be clearly seen from the pool deck. An effective technique is to toss a Secchi disk into the pool and determine if the 2-inch disk can be seen at the bottom–the black and red quadrants on the disk should be clearly visible through 15 feet of water. In actuality, though, water clarity can be measured as turbidity–the higher the turbidity, the more cloudy the water. Current quantitative indicators for measuring turbidity are the Nephelometer or Turbidimeter. NSF International recommends that pool-water turbidity should not exceed 0.5 NTUs. Most state codes do not allow turbidity to exceed 0.5 NTUs.

Filtration is critical to attaining ultimate water clarity. Traditional filtration media are still accepted by local and state health departments; however, aquatic operators are seeking greater clarity, with less effort using systems that are also easier on the environment. I will review alternative filtration technologies and how they operate so operators and managers can determine which system is best for their pool.

Sand Filtration

Sand filtration is the oldest type of pool filtration. Traditional sand filtration–whether it is a high-rate or rapid-rate filter–requires a medium that will gather the smallest particulate matter. The filters are designed to accept a granular medium. High-rate systems require fine high-grade silica sand, while a rapid-rate system uses a combination of sand and gravel. According to the NSPF Pool & Spa Operator Handbook, rapid-rate sand filtration will remove particles at a size of 50 microns, and high-rate sand will remove particles to 25 microns. Technological advancements to achieve smaller micron removal are now widely accepted in public-pool applications; zeolite and crushed glass are becoming acceptable sand-filtration media.

Zeolite is a granular volcanic material that is extremely porous. Manufacturers of these filtration products indicate that these media can remove particles down to 0.3-0.5 microns. Since the active ingredient is Clinoptilolite, it has a greater surface area with large pore spaces, allowing more dirt to be absorbed into the media. One of the greatest features of these products is the ability to remove chloramines and ammonia from the pool water.

Chloramines irritate bathers’ eyes and create odors (chlorine smell), found in indoor-pool environments. They are among a number of risks patrons and employees may face, particularly at indoor facilities. Most of the zeolite products require fewer materials, i.e., 50 pounds traditional sand; zeolite requires only 25 pounds. Mined naturally from volcanic rock, it is environmentally friendly. Because it is filtering smaller particles and is more efficient, the operator does not have to backwash as frequently, thus saving on water-replacement costs and time. Pool operators should be aware of specific guidelines, and follow directions when initially changing over to this product.

Recycled Crushed-Glass Sand Media

Page 1 of 3 | Next page

Related posts:

  1. Weighing The Options
  2. Swimming Pool Filtration
  3. Regenerative Media Filtration
  4. Troubleshooting Filters
  5. Swimming Pool Filtration
  • Columns
  • Departments