Water Testing Myth: Your Sight Can Test Pool/Spa Water

For those of us who have been “swimming laps in the pool” for a LONG time, we hear plenty of rumors, stories, gossip, shortcuts, and other “opinions” on many aspects of testing and treating pool/spa water.

Let’s talk about the most egregious “myth” that seems to perpetually hang around our industry and the real truth behind it.

Myth: An experienced operator can tell if there are any issues with water quality just by looking at the water.

Well … not really. It takes four of your five senses to perceive that something may be wrong. You have no idea how many calls and e-mails I’ve received or the conversations at trade shows I’ve had with pool techs who tell me things like …

  • “I’ve been doin’ [sic] pools for over 30 years and I can wave my hand over the surface and tell you the pH and chlorine levels.”
  • “I stick my finger in the water and taste it. I’m usually pretty good at it.”
  • “I just take my two bottles from my holster and put one drop of each right in the water and can immediately tell the chlorine and pH levels.”

Uh … no …

In the “real” world, you actually use four of your five senses to determine pool/spa health!

Sight: Even though a pool may look beautiful and inviting, it can hide some potentially bad issues. Take a closer look. Any visible algae? Any stains? Any obvious corrosion around steps or ladders? These are signs that all is not right. Water balance, also, is something you cannot see. You need to test for pH, total alkalinity, calcium hardness, and TDS plus know the temperature of the water to determine the Saturation Index (SI). If the SI is greater than +0.5 or less than -0.3 then your water is not balanced.

Hearing: You want to listen for any unusual sounds (like screeching noises or thumping). These noises could indicate something is wrong with the pumps and/or filter.

Smell: Smell the air around the pool. If you smell chlorine (particularly in an indoor environment), that’s not a good thing. A chlorine-like odor indicates the presence of high combined chlorine in the water, which may cause irritations and rashes. Combined chlorine must be removed by breakpoint chlorination.

Touch: If you’re not sure a stain is really a stain, or if it might be algae — feel it. If slippery, it’s algae, and a 30 ppm shock is recommended to get to the nucleus of the algae cell and disrupt its DNA so it cannot replicate. If it’s not slippery, it’s probably a metal stain. To remove, follow the instructions on your preferred stain-removing product.

Taste: No! No! No! A good service technician uses all of his or her skills to determine if a customer’s water is safe for bathers and that the equipment is functioning properly.