What size tank is this SunGrow Aquarium heater used for?
The size of the water heater is 13.5*2.5*1.7 inches. This has enough power to heat up max 3.5 gallon tanks .If you have a bigger tank consider using a different SunGrow aquarium heater. The heater runs between 8-13 W

Why is a fully submersible heater better than half submersible?
The fully submersible heater gives the aquarium hobbyist more freedom to place the heater wherever they prefer in tank. Each aquarist will decide on the ideal placement of the heater. The heat will circulate due to the flow of water from your filter. Ideally, your filter will thoroughly mix the water to prevent any torrid or cold zones creating a calm and tranquil habitat for your betta fish.

How will this heater help with energy conservation?
This heater has a very efficient heating module, which can transfer the electrical energy into heat energy at a rate that is 20% higher than the traditional heating rods.

How safe is this for my betta fish?
The heating rod is 100% safe to be submersed in your fish tank. The extra strength engineered plastic keeps your fish away from the heating element and prevents any exposure or collision with the actual heat source.

Precautions:
Please inspect the heating rod and power cord to check there is no breakage before use.

Product Instructions:
1.Submerge the heating rod fully into the water for 10 minutes to adapt to the temperature of the aquarium water.
2. When the water temperature is under 74°F, the aquarium heater starts working. When the water temperature reaches higher than 77°F , the aquarium heater stops heating. This ensures that the temperature stays constant between 74-77°F (24-25 ℃) which is the ideal temperature for Betta.

• ✔ ENSURE YOUR BETTA FISH GROW AND THRIVE --- It is absolutely essential that your aquaria should be heated between 75° and 77°F for optimal comfort and metabolic efficiency of your betta fish. Any temperature below 70°F will cause your bettas to enter a state of minimal activity and they will be stressed and miserable. Make sure Betta are at their optimal health and performance with this heater.
• ✔ CREATES THE IDEAL CONDITIONS FOR YOUR BETTA FISH --- Betta are tropical fish. That means they need warmer water to live in. This heater will create the ideal conditions for your betta fish to thrive in. The warm water will keep your betta fish calm and happy and make their metabolic process efficient. A few preconditions are required to allow it to run with maximum efficiency. The heater must be completely submerged in the water and the indoor temperature should be 62-75°Fahrenheit.
• ✔ INCLUDES SUCTION CUPS FOR EASY INSTALLATION ---- Easily install the SunGrow Betta Heater vertically or horizontally by using the built-in suction cups to attach to your tank. The best location to place the heater is in the stream of a powerhead or near the water flow, such as the outlet (or inlet) from the filter. This way the heat is evenly distributed throughout your tank.
• ✔ FULLY SUBMERSIBLE 100% WATERPROOF AQUARIUM HEATER--- The wattage of this aquarium heater is 10 watts and supports 1.5 gallon (5 liters) fish tank. Its exterior is designed with tougher than glass and it is completely sealed polymer quality that can be submerged into your tank. The heating element is surrounded by a thick plastic to ensure 100% protection of your fish. It is also explosion-proof, Shatterproof, durable and has an anti-scald surface. It has non-corrosive shell for strength which
• ✔ AUTOMATICALLY REACHES THE PERFECT PRESET TEMPERATURE --- The smart Betta heater by SunGrow has built-in electronic thermostat to automatically maintain water around 75 degrees Fahrenheit which is ideal for most tropical fish. It saves you from the trouble of constantly keeping a check on the temperature of your tank. It will automatically shut down when it will reach around the desired temperature, no manual adjustment is needed. This ensures that the temperature is not too high for your fish.