NJPools.club Community

Hey there! Fellow New Englander here with a hot tub obsession (and maybe too much coffee this morning ☕). I've had my TF-100 for years and it's been rock solid. Purple on the CH test is definitely weird—should be blue. Have you checked the expiration date on the reagents? Also, are you shaking the bottle well before each drop? Sometimes if it's been sitting, the chemicals can separate a bit.

**Early adopter of the TF-100 here**—I got mine as soon as it hit the market! Purple results aren't normal for CH. A few quick checks: 1. Make sure you're using the **right reagent** (R-0012 for CH). 2. Are you adding exactly 10 drops per the instructions? 3. Try testing a sample of **distilled water** as a control. If it still turns purple, the kit might be compromised. Let us know what you find!

Just finished a marathon training session and hopped on here! 🏃‍♀️ I've seen this before in my acrylic spa. Purple usually means **metals in the water**—like copper or iron—interfering with the test. New England water can be tricky. Have you used any metal sequestrants recently? Or maybe your fill water has high metal content. Try testing your tap water separately to compare.

**Science enthusiast weighing in!** 🧪 The CH test (calcium hardness) uses an indicator that binds to calcium ions, turning blue. Purple suggests a **pH interference** or **contamination**. Here's my hypothesis: - **High pH** (>8.2) can cause a purple tint. - **Cross-contamination** from other test reagents (e.g., dropping R-0007 into the CH vial by mistake). Test your spa's pH first. If it's in range, rinse your vials thoroughly with distilled water and retry.

Ah, takes me back to my blogging days troubleshooting my old cedar hot tub! 🌲 Purple results aren't necessarily a defective kit. In acrylic spas, **low calcium levels** can sometimes cause a purple hue instead of blue. Acrylic is softer than plaster, so you might need less calcium. What's your CH reading? If it's below 100 ppm, try adding a bit of calcium increaser and retest. Also, store your kit indoors—New England winters can freeze reagents!

Great points everyone! @BubbleBuddy's metal theory makes sense—my neighbor had purple tests from copper pipes. @DeckDiver34, could high pH really do that? Mind blown! 🤯 OP, give us an update after trying the distilled water control or checking for metals. And yeah, keep that kit away from freezing garages!