Blog
Is a Furnace Filter the Same as an AC Filter? (Same Machine, Two Seasonal Names)
Yes — in the overwhelming majority of homes, the furnace filter and the AC filter are the same physical filter in the same slot, becaus...
Can You Put Essential Oils on Your Furnace Filter? (Why the Viral Trick Is a Bad Trade)
No — and the interesting part is that the filter industry agrees with me. Dribbling essential oils on a furnace filter loads the media ...
Bad Air Quality Symptoms: What Each AQI Band Does to Sensitive and Healthy People, the Two Timescales Nobody Separates, and the Red Flags
Bad-air symptoms run on two different clocks, and mixing them is how people misjudge their days. The fast clock — minutes to hours: eye...
Does a Higher MERV Rating Restrict Airflow? (the Pressure-Drop Numbers)
Yes — but by less than the internet fears and more than the box admits: a clean 1″ filter's initial resistance climbs roughly 0.05–0.15...
Do Houseplants Really Clean Your Air? The 1989 NASA Study, the 2019 Review That Walked It Back, and the Drexel Arithmetic
The "plants purify air" belief traces to a real 1989 NASA report — which ran in sealed, fridge-sized chambers, injected a single pulse ...
Radon in Your Water: Test the Air First ($15) — the Sequencing Trick That Saves $85
Quick answer: Water radon has no federal limit — EPA proposed 300 pCi/L in 1991 and never finalized it, so state guidance carries the l...
VOCs in Your Water: the 21 Regulated Compounds, Breakthrough Physics & the Gas-Station Radius Check
Quick answer: VOCs (volatile organic compounds) are a family of 21 EPA-regulated solvents and fuel chemicals — benzene, TCE, MTBE, carb...
Coliform in Your Water: Reading the Report Right — total vs. fecal vs. E. coli, and the Retest That Saves $800
Quick answer: Total coliform by itself is an indicator, not a pathogen — its presence says "a pathway to contamination exists," not "yo...
Mercury in Your Water: 2 ppb, Where Exposure Actually Comes From & the Heavy-Metal Trio Table
Quick answer: Inorganic mercury's drinking-water limit is 2 ppb (0.002 mg/L) — and the honest context most pages omit: drinking water i...
Chromium-6 in Your Water: the Federal 100 ppb vs. California’s 10 ppb — Two Standards Explained
Quick answer: The federal limit regulates total chromium at 100 ppb; hexavalent chromium (Cr6, the "Erin Brockovich chemical") has no f...