Pump Room Survival Guide: Logging Your Swimming Pool Test Kit Results

In Blog by David Stringfellow

Pool log image

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In Kate’s last installment, “Basic Guide to Choosing a Test Kit”, she taught us about what type of test kits are available and hopefully left you, the always intrepid pool operator, with a few ideas of what is out there and how best to choose the test kit for your needs. So now here you are, with your shiny test kit ready to take on the world (or at least the pool)… now what?

First, read the directions! Then, keep them on hand in a safe place. Should you find that your pump room pet Cthulhu eats those directions, as often happens, keep in mind that they’re often also available online. All of the test kits that I’ve worked with have printable directions right on the good ole Google box and if that doesn’t work, take a few minutes out of your cat watching schedule on YouTube and search for your test kit… most likely there is an instructional video. Or, better yet, call your friendly Pool Guru, a.k.a. me.

But I digress and you are probably wondering what this has to do with an axe wielding, flannel wearing, bearded arborist. Nothing! What kind of logging were you thinking about? With a great test kit comes great responsibility. I’m sure that this is not news to anyone reading this, but to state the obvious, all of those tests you are conducting need to be written down somewhere. In fact, your state Health Department most likely requires that you take a minimum amount of certain tests that have to be written down and easily accessible.

So what should be logged? Everything you test for and then some. Sure, pH and Free Chlorine are the staples and hopefully the LSI once a week but here is a brief list of what I tell my clients to note as often as they can:

  • pH
  • Free Chlorine
  • Combined Chlorine
  • Flow rates
  • Total Alkalinity
  • Calcium Hardness
  • Chemistry Controller readings
  • Bather Load
  • How much of what chemical(s) have been added and when
  • Date / Time / Initials of test taker


Other than making friends with your inspector, there are other benefits of keeping meticulous records of your water chemistry:

  • Early detection of leaks. If your Calcium Hardness or Salinity is starting to plummet, especially if you haven’t backwashed between readings, this could indicate a leak.
  • Budgeting. After a few months of checking your chemistry and adding chemicals for balancing, you should have a great idea of how much of what you are going to need.
  • Equipment maintenance. Noticing that your pH or Free Chlorine is going wonky? Maybe it’s time you clean or replace the chemistry controller probes.


The list could go on, but I’ll leave you with a question of my own instead. What are you logging and how often?