Mocatrend HL-288 300W Watt Submersible Aquarium Heater Fish Tank Water Heater - for 200-250L

The thermostat or the calibration on this heater is off. I like my water to be between 82-83 degrees (I keep German blue rams, they like the warmer water - similar to discus). The upper limit is 84 degrees but when it gets above that, I don't like it. Oxygen levels can drop in water that's too warm. Anyways, this heater will be set at around the 80 degree mark, the water will be 83, and the dang thing will still turn on! It would be a good idea to use an external thermostat with this heater, in all honesty. However, this heater is inexpensive and I love the fact that it comes with a cage to keep plants and animals off of it. Given the price and cage, I'm going to keep using it but I'm going to have to hook it up to an external thermostat to be able to rely on it.Or I'd be willing to exchange it but only once I've received a new unit.So, exercise caution with this heater.I am editing this review: do not use this heater. It is very inconsistent. I have it set to the 76 degree range and it's still heating the tank up to 83 degrees. It just doesn't work and I can't justify purchasing a $30 thermostat to run a $16 heater when purchasing a replacement heater will be less expensive. I will be returning this item and I recommend against anyone purchasing this heater if you value consistency.

Works great on my 75 gallon tank. 4 stars because as stated in other reviews the temp doesn't match the dial. I have a 5 degree variance, set to 72 thermometer reads 77. Once you know the difference in degrees you are set, great little heater. Please fix the temp guage for future buyers.

On our Costa Rica finca, we built a single room cabina with outside kitchen and bath. Struggled a bit to find an economical solution to heating the shower water but this aquarium heater did the trick! Takes about 24 hours to warm our 250L gravity-fed water tank to a comfortable temperature. After 48 hours, the shower is on the edge of hot. So simple, easy to replace and sips electricity, which is expensive here (27c/KWh). It's been working for over a year now, but if it ever gives up, we'll get another for sure.

The heater does the job. I'm a bit disappointed because it is too tall for my tank even though the description said it was suitable for the size I have. The instructions were definitely written by someone whose' primary language was not English. The grammatical errors make for a giggle but make the company look unprofessional.

Works amazing in my 75 gallon tank, only issue I have is it needs to be turned up warmer then what it says to get the desired temperature you want.

Am using this in our new 55gal fish tank. We had 2 100watt heaters that just wouldn't do it. in combination with this works excellent.

Works great for a 55 gallon tank! I was worried that I would need 2, but it works great!

I purchased this without knowing that it was made more for a 10+ gallon tank, instead of my 3.5 gallon tank. I haven't tried it because I am not ready for the upgrade just yet.