South Shore Retail MaxxHeat 300W Aquarium Heater – Durable with Protective Casing – for Fish Tanks, Stock Tanks, Koi Ponds, Outdoor Ponds, and De-Icing – Veteran-Owned Small Business

I currently am using this heater in our 200 gallon outdoor turtle pond/fountain. The temp here drops to the low 40°s at night. Even with the waterfall running all night long, this heater still keeps the water warm enough for the turtles and fish. I usually keep it set to 75 degrees. With the pump and two tier waterfall running all night, the coldest the water has gotten is down to 65° by morning. With the pump and waterfall off at night, the water temp is usually about 71 or 72° by morning.You won't find a stronger heater anywhere at this low of a price that works this good.

I used it for a small pond approximately 40 to 50 gallons maybe less but it kept the warm enough so I didn’t have to transfer the fish

I haven't used this heater yet, but the price was a bargain and it looks like many other generic chinese made 300watt submersible heaters.

I've had this heater for 3 weeks and I was starting to like it, but unfortunately I came out to my pond last night clocking in @ 65 degrees F, so I checked my heater and it was completely cold to the touch. I pulled the plug and then put it back in to reset. The light would come on initially but then goes out within a few seconds. Being pretty impressed with this one when I first got a hold of it, I bought a second one a week after, but I'm now wondering if this was a mistake. I'm hoping this was a one off, and would love a way to get a replacement but I threw the box out, unfortunately. Hopefully the manufacturer/seller will see this and figure a way to work something out.

I think this heater might be the best bang for the buck on Amazon. It can heat a tank faster than my other heaters for half the price. It is large but in my case that wast an issue at all. Fantastic accuracy, I have 3 thermometers on my tank and the dial matches all of them. Very high performance for $12

The media could not be loaded.  Keeps her water perfect! I love it! And the seller is amazing as well.. There was a small issue that got fixed so fast!! I ABSOLUTELY recommend!!

I purchased a 300 W heater for my 55 gallon tank. It works really well for about a month and a half before it crapped out once I figure out how to contact the seller. They were very helpful very polite and the heater is definitely worth a second try but I would definitely buy from the seller again.

This is a really nice heater. Clearly well made and a nice design, but it's huge! No way this fits in my 10 gallon tank. Just too big. 15" long. If that works for your tank, you'll be happy with this. Great price for a heater of this size.