1 of 1 people found the following review helpful
Boyu HT-825 (A Chocolate Teapot),
Verified Purchase(What is this?)
This review is from: 25W Aquarium Fish Tank Submersible Heater (Misc.)
Firstly it should be noted that the make of the heater I received does not resemble the picture in any shape or form. The heater itself is a stubby design Boyu HT-825 and is only adjustable between 16-32°C, not the 20-34° as stated on the listing.
I placed the heater in a 5 litres of water to get an idea of what temperature offset was. The ambient temperature was 18°C and the initial temperature was 17°C (I have a good thermometer) and the water was left for 24 hours. After setting the dial to 26°C I was able to maintain a rough temperature of 20°C. To actually maintain a suitable temperature for tropical fish you would have to place the dial at maximum. If you then wanted to increase the temperature for different species or for treatment you have no where to go.
This heater cannot sustain 5l let alone 20l in an aquarium. Should your aquarium be in a draft then there's no chance that this heater will maintain a correct temperature. Buy cheap, buy twice!