I gave this unit one star for its risk factor. I bought this in November and up until last week it was working great with my 2.5 gallon, which is about two months. Noticing my faucet was lethargic and the water temp was around 30c, I took it off immediately and noticed these hard bumps on the heater that weren't there before. Having seen many reviews with similar experiences I doubt this is the only issue with my device so I would recommend avoiding this product.
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