Bests & Worsts Reviews from Amazon

Alright, so first things first. These heaters work, they just do not work as advertised. They do not provide a 21 F temp range. Maybe 15 in ideal conditions, and much less than that in semi-cold environments (60 F). I have three 300W's, 1 150W, and 1 100W. A 300W is perfectly suitable for a 40-gallon breeder. A 100W is suitable for a 10G. A 150W is suitable for a 20G. But, when you crank these devices to maximum power, an indoor pond of fewer than 180 gallons including an insulated bottom will not go over 75F from 60F. That's a measily 15 degrees with some serious power usage: 1,150 watts. This is not ideal for my Tilapia which require 80-86 for optimal growth and breeding. The black things on the bottom always come off. I don't even know why they bother. I believe the included (and very ghetto) temperature gauge is purely an incentive to make a cheap and inefficient product seem a good alternative to more expensive heaters. If you are running basic tanks indoors, and do not care about looks, or having to constantly fiddle with the temperature gauge knowing that it's never going to be the temp it says, this may be a bargain for you. I don't mind using them in my 40G breeder, 20GL or 10G Fry tanks. However, these are cheap for a reason. I would take that into consideration before buying them depending on your particular needs. Also, raising the prices 3+ dollars is, well, how do I put it - sending me in a new direction. These were barely a bargain due to the flaws before. I will not pay those prices for an inferior product; I will drop extra money on a better heater. I suggest you are more honest in your advertising, if my fish didn't need the heaters to survive I'd already have returned them as products that do not work as advertised. I highly advise against these heaters for anything but cheap aquarium setups. The price of all the heaters I bought combined has me wishing I'd chosen to raise trout instead. It takes my aquaculture hobby which uses next to no power and demands at least another 300 watts on top of the 1,150w I already have. That's a lot of power, which creates a big power bill. I advise you to go with another brand and save yourself this headache if you can afford too.