I don't think I noticed anything different, but then again the purifier was running non-stop, so I can't really say whether not having it run would have impacted that tank. However, it certainly helped the inside air quality in the house - which is the first priority. LIving in 200-300 AQI for weeks at a time is no joke, and smoke gives me headaches anyway - so, it was worth the price tag. I researched a lot of purifiers - there are certainly cheaper ones out there, but the Alen filters are large and have pounds of carbon in them, so are more substantial than many others I looked at. I think mine is rated at like 1,000 sq/ft every 30 minutes or something in that area...