A big part of pool ownership is keeping the water chemistry balanced. But what does that entail? How do you take a water sample? How much pool water is needed for testing? Are there certain times that are better for testing your water? To help answer these questions and more we’ve put together a quick list of tips when it comes to swimming pool water testing.
The Water Sample Container
It may seem irrelevant, but the container in which you collect your pool water sample is quite important. Although you don’t actually have to use a container specifically made for pool water samples, you’ll want to make sure it’s clean and well rinsed. And you’ll want to rinse it between tests for pH, alkalinity and chlorine. Don’t use containers that held vinegar, pickles, chemicals or any other acidic or alkaline substance as the residue will tamper with your results. An ideal water sample will be at least 250 ml.
Where to Collect the Water Sample
When collecting the water sample, it’s recommended to submerge the sample container elbow deep into the pool before allowing it to fill up with water. You’re looking to get the container about 45 cm underwater as the surface of the pool will harbour contaminants and debris that will affect the test results. You also want to avoid the areas around the return jets as there will usually be higher concentrations of chemicals around them. If your pool has a deep end, it’s best to take your sample from there as well.
When to Collect the Water Sample
Collecting your water sample in the morning is ideal as sunlight degrades chlorine. Morning collection allows the water to properly circulate through the night and give you a relatively stable reading. You’ll want to avoid taking any water samples for 24 to 48 hours after adding chemicals. Obviously, these additives will skew your results. Rainwater can also increase the acidity of your pool, so you shouldn’t take a water sample while it’s raining. Allow the water to fully circulate for about eight hours after a rainfall before taking a sample.
When to Test the Sample
It’s best to test your water sample as soon as possible after taking it. If you let it sit all day long or let it be exposed to long stretches of sunlight, your results will be distorted. If it rains soon after you take the sample, you can be assured that your tests won’t be indicative of what’s actually happening inside your swimming pool. And if you’re taking your pool water to your dealer to have it tested, it’s best to do this right away rather than having the water sample sit all day while you’re at work before you can run your errands.