A filter in a St. Louis home works quietly, which is why it is easy to forget. Whole-house point-of-entry units near where the main line comes into the house, and smaller point-of-use units at a kitchen sink or refrigerator line, both need changes on a regular schedule. A written log of those changes turns guesswork into a short history you can read in a minute.
What to write down at each change
- The date the cartridge or media was changed.
- Where the unit sits, such as the entry area in a basement or the cabinet under the kitchen sink.
- A plain description copied from the label, including the type of filter media and its stated purpose.
- Your water source at the time, city supply or private well.
- Anything you noticed before the change, such as weaker flow, a taste or odor difference, or cloudiness in a glass.
- Who did the work, you or a professional.
Why the source matters in the St. Louis area
Many homes in the city and older suburbs connect to the municipal supply, while homes in outlying parts of the region may rely on a private well. The source affects what a filter is meant to handle, so write it down every time. Municipal supply conditions can also shift during the year, and a dated log lets you connect a change you noticed in the glass with what the water was doing that season. A log will not tell you what is in the water, but it will tell you when something changed in your home.
Setting up a log you will actually keep
- Choose one place only. A card taped inside a cabinet door near the unit, or a single note on your phone, works well.
- Write the entry the same day you do the work, while the label is still in front of you.
- Photograph the label and the unit's location, and keep the photos in one album.
- Store receipts and service paperwork in the same folder as the log.
- Set a reminder for the next change based on the date printed on the filter or in its instructions, not on memory.
Reading the log over time
After a few entries, the log starts to show patterns. A filter that always seems to need changing early may be working under more load than its label suggests, and a unit changed late may explain a drop in flow or a taste change you noticed in the weeks before. Write a short note whenever something seems off, then compare it to the dates in the log.
Pairing the log with a water test
A log records what you did. A water test records what the water contains. Home test kits can show general characteristics such as hardness or chlorine, while a certified laboratory can run the specific checks a homeowner may need. Use the log to decide when a test is worth running, for example after a filter change, after a visible change in the water, or before a seasonal review. Keep each test report in the same folder as the log so the two can be read together.
When to call a professional
If a unit leaks, loses flow suddenly, or shows signs of damage, stop and write the date and symptoms in the log before doing anything else. Then contact a licensed plumber who works in the St. Louis area to look at it. Ask whether the repair or replacement is covered by any warranty, and keep the answer on paper. A complete log will make that visit faster because the history is already written down.