In the spirit of keeping our economy going, we’re going to blog a near-live time problem. Here’s today’s email from a Midwestern spa tech. Her job is on the line. Can the Pool and Spa Master help her keep her job? We’ll see.
“I stumbled on your website trying to find a solution to an icky mess of a problem I’m having with a spa at my current job. I say current because I am afraid if I don’t figure this out it may not continue to be my place of employment! I work at a shop that sells spas and what not, chemicals, blah, blah… SO I believe I may have caused the pH to go wacky or something on a couple of different occasions. I used to think there was no way I could have caused these problems. I had been listening carefully to what I had been taught about chemicals, following directions on the bottles and so forth. But there have been a couple of occasions where it seems that by my trying to adjust the balance, the chemistry has gone nuts. The water stinks like halitosis, has a green sludgy look and gets a bit foamy as well.

This has occurred after adjusting the pH, waiting a bit and adding sanitizer. It seems at first like it will be okay and then it just…turns. Like it’s rotting or something. After about a day, I added some shock. Didn’t help. In fact, it just caused the sanitizer level to read off the charts, the water to get greener and stink worse! Man, I don’t want to lose my job. No one else seems to know what exactly I could have done to cause this problem and how to fix it. Can we fix it without having to dump it out? This would be the 4th time we’ve had to empty and refill a tub! (in 4 months) Awful, I know. Please help me! I need a paycheck!”
Clearly, the Pool and Spa Master needs more information, so here’s my reply to our frazzled spa tech:
“A few questions first,
1) What is the TDS (Total Dissolved Solids)?
2) What is the Total Alkalinity reading?
3) What is the Calcium Hardness reading?
4) What is the chemistry of the fill water and the makeup water (from the spigot)?
5) What is the source of that water?
6) What kind of disinfectant are you using in the spa?
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Our spa tech got back to me, and noted that the tub was drained when she got back to work.
However, let’s discuss the reasons why I asked some of the questions.
TOTAL DISSOLVED SOLIDS AND YOUR UNRULY TEENAGE MOMENTS: TOTAL ALKALINITY & pH
If you’re a pool or spa dude, there’s nothing sexier than asking, “What’s your spa’s TDS?” It’ll rope ‘em in every time. I mean, talk about an ice-breaker! (How do you think I met my wife?)
BTW, TDS is leftover minerals from your spa’s evaporation process. Remember distilling water in high school chemistry? Your local water will have a natural TDS to begin with. As your use your spa, not only are hard bits and pieces left behind, but the tub is distilling as well—AKA TDS.
Now take an 8-ounce water sample to your local pool and spa shop, and ask them to test it for you.
High Total Dissolved Solids (TDS)—which is any reading over 1500 ppm–will interfere with your sanitizer’s ability to perform as designed. If your spa’s water reads over 1500 ppm, dump the chump. Trust me; it’s your only alternative.
“But the guy at the spa shop said my water was only 800 ppm, and my spa’s water still looks and smells like a rank pond.”
So, cross off TDS as a contributor, and move on to my next question “What is your total alkalinity reading?”
Why? If your total alkalinity is unbalanced (not within 80-120 ppm) it’s likely that your pH is off the scale and not under control. This scenario, again, affects your sanitizer’s ability to perform. Sanitizers work best in a perfect world.
A pH fluctuation by 2/10 of a ppm can make your disinfectant 70-80% less effective.
Remember those unruly teenager moments? Just think of your spa’s unruly total alkalinity and pH as a teenager that needs measured control. Always, always, always balance your total alkalinity FIRST (between 80-120 ppm). Once your total alkalinity is perfect you will then balance the pH (between 7.2 to 7.6 ppm).
Yes, like teenage moments, you may have to use a LITTLE bit of sodium bicarbonate, sodium carbonate and sodium bisulfate to get your total alkalinity and pH balanced, but it is the first step to preventing all the calamities that our friend with her job-at-risk experienced.
…To be continued.